was the expression a^2-b^2 = (a+b)(a-b) invented or discovered?
Answer:
the expression is invented
The radioactive isotope of lead, Pb-209, decays at a rate proportional to the amount present at time t and has a half-life of 3.3 hours. If 1 gram of this isotope is present initially, how long will it take for 70% of the lead to decay? (Round your answer to two decimal places.)
Answer:
5.73 hours
Step-by-step explanation:
70% decay means 30% remains
.3 = (1/2)^(t/3.3)
take the log of both sides
log.3 = t/3.3 * log1/2
Divide both sides by log 1/2
log.3 / log1/2 = t/3.3
use calculator
1.736965594166206 = t/3.3
multiply both sides by 3.3
5.73198646074848 = t
rounded
t = 5.73 hours
Which ones are correct?
Answer:
Th answer is D
Step-by-step explanation:
NEED HELP ASAP! Which condition would prove JKL ~ XYZ?
The school that Willie goes to is selling tickets to the annual talent show. On the first day of
ticket sales the school sold 12 senior citizen tickets and 5 child tickets for a total of $102. The
school took in $156 on the second day by selling 14 senior citizen tickets and 12 child tickets.
Find the price of a senior citizen ticket.
Answer:
11
Step-by-step explanation:
all you need to do is divide 156 dollars by 14 citizen
what is the ordered pair for the equation -7x+3y=2
Answer:
Step-by-step explanation:
3x^2=12 solve the equation algebraically?
Answer:
x = 2
Step-by-step explanation:
Problem: 3x^2 = 12
Divide both sides by 3 to isolate x: x^2 = 4
Take the square root of both sides of the equation: x = 2
Answer: x = 2
The factory has 6 cutting machines. Each cutting machine cuts 105 parts every 3 minutes. How many parts can all 6 cutting machines cut in 1 minute
Answer:28
Step-by-step explanation:
which numbers in the set (2, 3, 4, 5,) are solutions to the inequality 19- 4x>3
Answer:
2 and 3
Step-by-step explanation:
Given the set (2, 3, 4, 5,) and inequality 19- 4x>3
To obtain which number gives a solution, we test each value in the set ;
19- 4x>3
For x = 2
19- 4(2)>3
19 - 8 > 3
11 > 3 (true)
x = 3
19- 4(3)>3
19 - 12 > 3
7 > 3 (true)
For x = 4
19- 4(4)>3
19 - 16 > 3
3 > 3 (false )
For x = 5
19- 4(5)>3
19 - 20> 3
-1 > 3 (false)
Solve for z
3z-5+2z=25-5z
Answer:
z=3
Step-by-step explanation:
1. collect like terms
5z-5=25-5z
2. Move the variable to the left hand side and change its sign
5z-5+5z=25
3. Collect like terms
10z=25+5
4. Divide both sides of the equation by 10
z=3
The solution to the equation is z = 3.
To solve for z in the equation 3z - 5 + 2z = 25 - 5z, we can simplify and combine like terms on both sides:
3z + 2z + 5z = 25 + 5
Combining the terms on the left side gives:
10z = 30
Next, we isolate the variable z by dividing both sides of the equation by 10:
(10z)/10 = 30/10
This simplifies to:
z = 3
Therefore, the solution to the equation is z = 3.
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Find the value of x.
9514 1404 393
Answer:
103
Step-by-step explanation:
The sum of angles in a quadrilateral is 360°, so the measure of x° is ...
x° = 360° -127° -90° -40° = 103°
x = 103
Answer:
The measure of x is 103 °.
Step-by-step explanation:
Concept :- As we know that sum angles of quadrilateral is 360 ° so, to find the measure of x.
Firstly add all the angles that we have given and subtract from 360 ° and we get the vue of x.
Solution :-We know that The sum angles of quadrilateral is 360 ° , Hence, value of x =
x + 127 ° + 90 ° + 40 ° = 360 °
x + 257 ° = 360 °
Subtract 257 ° from 360 °
x = 360 ° - 257 °
x = 103 °
Therefore, The measure of x is 103 °.
The following information was collected on 20 randomly chosen high school students, which compared their IQ score to musical aptitude.
Row IQ Score Mus.Apt.
1 95 30
2 106 37
3 110 35
4 104 28
5 98 17
6 114 45
7 123 33
8 100 18
9 98 24
10 88 18
11 102 30
12 105 30
13 111 32
14 106 33
15 110 38
16 143 42
17 106 40
18 98 20
19 104 23
20 97 25
Descriptive Statistics
Variable N Mean Median TrMedian StDev SEMean
IQ Score 20 105.90 104.50 104.83 11.60 2.59
Mus.Apt 20 29.90 30.00 29.78 8.27 1.85
Variable Min Max Q1 Q2
IQ Score 88.00 143.00 98.00 110.00
Mus.Apt 17.00 45.00 23.25 36.50
Regression Analysis
Predictor Coef Stdev t-ratio p
Constant -22.26 12.94 -1.72 0.102
IQ Score 0.4925 0.1215
s= 6.143 R-sq= 47.7% R-sq(adj)= 44.8%
A. What is the equation of the least squares regression line that would be used to predict musical aptitude from an IQ score? Be sure to define any variables used.
B. Calculate and interpret a 95% confidence interval for the slope of the regression line.
C. Is there a significant relationship between IQ score and musical aptitude? Give a statistical justification to support your answer. Assume conditions for regression inference are satisfied. Test at
α=0.05.
Answer:
Y = 0.4925X - 22.26 ;
(-12.413, 13.398) ;
Yes, there is
Step-by-step explanation:
X = IQ Score ; Y = musical aptitude
The regression equation from the table given using the slope and intercept coefficient :
Y = 0.4925X - 22.26
0.4925 = slope ; Intercept = - 22.26
The 95% confidence interval of the slope :
Confidence interval = b ± Tcritical*SE
Tcritical at 95%, df = n - 2 = (20 - 2) = 18
Tcritical = 2.1009
b = slope Coefficient = 0.4925
S.E = 6.143
Hence, we have :
Confidence interval = 0.4925 ± (2.1009 * 6.143)
Confidence interval = 0.4925 ± 12.9058287
Lower boundary = 0.4925 - 12.9058287 = - 12.413
Upper boundary = 0.4925 + 12.9058287 = 13.398
(-12.413, 13.398)
There is a significant relationship between IQ score and musical aptitude because, 0 is within the confidence interval obtained.
Hamburger Heaven is having a lunch special where customers buy one -pound cheeseburger and get one free. If they set aside pounds of meat, how many -pound cheeseburgers can they make?
Answer:
hey um how many pounds of meat do we know that yet?
Answer:
49 hamburgers
.For small training sets variance may contribute more to the overall error than bias. Sometimes this is handled by reducing the complexity of the model, even if the model is too simple. Why do you suppose this is the case
Answer:
Bias is the difference between the average prediction of our model and the correct value which we are trying to predict and variance is the variability of model prediction for a given data p[oint or a value which tells us the spread of our data the variance perform very well on training data but has high error rates on test data on the other hand if our model has small training sets then it's going to have smaller variance & & high bias and its contribute more to the overall error than bias. If our model is too simple and has very few parameters then it may have high bias and low variable. As the model go this is conceptually trivial and is much simpler than what people commonly envision when they think of modelling but it helps us to clearly illustrate the difference bewteen bias & variance.
4
)
5 + 15x
42x + 4
A) -2
C) -10
B) 3
D) -8
Answer:
D
Step-by-step explanation:
D
ITEM
UNIT COST
Belt
$1,500
Handbag
$11,540
Leather Gloves
S2,999
Sunglasses
$8,680
Watch
$15,460
14" Satin Bonnet
$1,127
1. What will be the cost for an 18" satin bonnet?
Answer:
1,449
Step-by-step explanation:
Anyone know these answers
Answer:
Step-by-step explanation:
Is a lamp bigger than a mug?
yes of course it's bigger, put a mug next to a lamp and there you will see it
Answer:
Whether you have your hot drinks in a ceramic or glass mugs, the difference is ... light kind of weight over the mugs when compared to the ceramic cup. ... can retain the heat for a much longer time duration than the glass cup.
Step-by-step explanation:
Hope this answer helps you :)
Have a great day
Mark brainliest
HELPPPPPP PLEASEEEEE ILL GIVE BRAINLIEST AND POINTS
(you dont need to answer them all but at least help me with a couple)
1) Explain Uganda’s ABC program in the fight against HIV/AIDS
2) Why has the Ugandan government pushed Abstinence as a means of combating the spread of HIV/AIDS?
3) What risks are involved with the use of condoms in combating the spread of HIV/AIDS?
4) On a separate piece of paper, construct a population pyramid to illustrate the current age groups infected by HIV/AIDS in Uganda.
Answer:
They called the campaign "ABC"--Abstain, Be faithful, or, as a last resort, use a Condom. Within a few years, Uganda had developed what researchers call a "social vaccine" against HIV: cultural norms about sexual responsibility, preached in clinics and public schools, as well as churches and mosques.
Step-by-step explanation:
The ABC strategy is credited for bringing the HIV/AIDS epidemic under control in Uganda. By promoting abstinence, being faithful, and condom use, safe(r) behaviors have been identified that are applicable to people in different circumstances.
1.) The ABC strategy is credited for bringing the HIV/AIDS epidemic under control in Uganda. By promoting abstinence, being faithful, and condom use, safe(r) behaviours have been identified that are applicable to people in different circumstances.
2.) Because the people for whom the propaganda is done are mostly children above 10, who tend to start having sex at an early age.
3.) A reexamination of HIV seroconversion studies suggests that condoms are 90 to 95% effective when used consistently, i.e. consistent condom users are 10 to 20 times less likely to become infected when exposed to the virus than are inconsistent or non-users.
4.) illustrate the photo
Find C.
Round to the nearest tenth.
20 ft)
22 ft
B
18 ft
А
look at pic 10 pts will mark brainilest
ered
Christine(C) and two of her friends. Bianca B) and Travis(7), won first place for a marketing case competition. They received an amount of $3,600, however,
they decided to share the prize in the ratio of the amount of time each of them spent on the marketing case. If Christine spent 4 hours, Bianca spent 6 hours.
and Travis spent 8 hours, what would be each person's share of the prize?
f2.00
jon
aC:600.B:1400,T:1300
b. C:600.B:1200.T: 1600
c
C:800.B:1200.T:1600
Answer: C:800.B:1200.T:1600
Step-by-step explanation: If the ratio is proportional to the time spent on the marketing competition, then we can add the hours up: 4+6+8=18. Total amount divded by total hours -> 3600/18=200. So each hour worked is 200 dollars. Christine worked 4 hours, 4*200=800, Bianca worked 6 hours, 6*200=1,200, and Travis worked 8 hours, 8*200=1,600.
i will mark brainliest please help me on this question!
B. The data set is skewed to the left.
select the correct answer. The capacity of a circular bowl varies directly with the cube of its diameter. How does the capacity of the bowl change when the diameter is doubled? a. the capacity is multiplied by 8. b. the capacity is multiplied by 2. c. the capacity is multiplied by 1/8. d. the capacity is multiplied by 1/2.
Answer:
A
Step-by-step explanation:
got it right on the test
In a directly proportional relationship, increasing one variable will increase another. The correct option is A.
What is the directly proportional relationship?Let there are two variables p and q
Then, p and q are said to be directly proportional to each other if
p = kq
where k is some constant number called the constant of proportionality.
This directly proportional relationship between p and q is written as
p∝q where that middle sign is the sign of proportionality.
In a directly proportional relationship, increasing one variable will increase another.
Now let m and n be two variables.
Then m and n are said to be inversely proportional to each other if
[tex]m = \dfrac{c}{n} \\\\ \text{or} \\\\ n = \dfrac{c}{m}[/tex]
(both are equal)
where c is a constant number called the constant of proportionality.
Given that the capacity of a circular bowl varies directly with the cube of its diameter. Therefore, the relationship can be written as,
Volume of the bowl ∝ (Diameter of the bowl)³
V₁ ∝ (D)³
Now, if the diameter of the bowl is increased and made double. Then the volume of the bowl will be,
Volume ∝ (2 × Diameter)³
V₂ ∝ (2D)³
V₂ ∝ 8(D)³
V₂ ∝ 8 V₁
Thus, when the diameter is doubled then the capacity of the bowl changes to 8 times the initial.
Hence, the capacity is multiplied by 8.
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The school newspaper surveyed 100 commuter students and asked three questions. First, students were asked how many courses they were currently enrolled in. Second, the commuter students were asked to estimate how long it took them to drive to campus. And third, they were asked their heights. Identify the type of random variable being measured by each.
Answer:
The number of courses they were currently enrolled in is a discrete random variable.
The time it took them to drive to campus is a continuous random variable.
Their heights is a continuous random variable.
Step-by-step explanation:
Random variables:
Random variables can be classified as continuous or discrete.
Discrete variables are countable numbers(0,1,2,...), while continuous variables can assume decimal values.
First, students were asked how many courses they were currently enrolled in.
Can be 0,1,2,... that is, has to be a countable number, so the number of courses they were currently enrolled in is a discrete random variable.
Second, the commuter students were asked to estimate how long it took them to drive to campus.
Can be for example, 10.5 minutes, half an hour, that is, can be represented by decimal values, and thus the time it took them to drive to campus is a continuous random variable.
And third, they were asked their heights.
Can also be decimal numbers, so continuous.
Can anyone help? Please and thank you!
Answer:
[tex]csc(\theta)=\frac{6}{5}\\\\sin(\theta)=\frac{6\sqrt{11}}{11}\\\\cot(\theta)=\frac{6\sqrt{11}}{11}[/tex]
Step-by-step explanation:
This problem asks that one to finds the value of some basic trigonometric functions. Remember, the trigonometric ratios in a right triangle are the following,
[tex]sin(\theta)=\frac{opposite}{hypotenuse}\\\\cos(\theta)=\frac{adjacent}{hypotenuse}\\\\tan(\theta)=\frac{opposite}{adjacent}[/tex]
One also has the reciprocal functions for trigonometric ratios these are as follows,
[tex]csc(\theta)=\frac{hypotenuse}{opposite}\\\\sec(\theta)=\frac{adjcanet}{opposite}\\\\cot(\theta)=\frac{adjacent}{opposite}[/tex]
This problem gives on the information that the side adjacent to the angle ([tex]\theta[/tex]) has a measure of (5) units. The hypotenuse, side opposite the right angle measures (6) units.
One can use the Pythagorean theorem to solve for the unknown side. The Pythagorean theorem states the following,
[tex]a^2+b^2=c^2[/tex]
Where (a) and (b) are the sides adjacent to the right angle of a right triangle. (c) is the side opposite the right angle; the hypotenuse. Substiute the given values in and solve for the unknown,
[tex](5)^2+(b)^2=(6)^2\\25+b^2=36\\b^2=11\\b=\sqrt{11}[/tex]
The problem asks one to find certain ratios. To do this, simplify substitute the sides into their respective positions in the ratio.
[tex]csc(\theta)=\frac{hypotenuse}{opposte}=\frac{6}{5}[/tex]
[tex]sin(\theta)=\frac{hypotenuse}{opposite}=\frac{6}{\sqrt{11}}=\frac{6\sqrt{11}}{11}[/tex]
[tex]cot(\theta)=\frac{adjacent}{opposite}=\frac{5}{\sqrt{11}}=\frac{5\sqrt{11}}{11}[/tex]
A sample of 340 students in a high school were asked how many times they go to their locker each day. 137 of those surveyed said that they go to their locker at least 3 times each day. Calculate the sample proportion of students who go to their locker at least 3 times each day. Either give the exact fraction or decimal, or round to three decimal places.
Answer:
The sample proportion of students who go to their locker at least 3 times each day is 0.403.
Step-by-step explanation:
Sample proportion of students who go to their locker at least 3 times each day.
The sample proportion of students who go to their locker at least 3 times each day is the number of students who do this divided by the size of the sample.
In this question:
137 go to their locker at least 3 times each day, sample of 340 students. So
137/340 = 0.403
The sample proportion of students who go to their locker at least 3 times each day is 0.403.
What IS the distance between the points (7, 8) and (-8, 0) on a coordinate grid?
Answer:
17
Step-by-step explanation:
Can someone help me please
Answer:
4(8+n)
(n×8) + (n×4)
8(n+4)
(n×8) + (n²)
Step-by-step explanation:
just very basically calculate or transform the expressions. pay attention to what is a multiplication, and what is an addition (sometimes the brackets try to suggest something else than what is actually there).
Can some one help me with this please
Answer:
First integer = 19
Second integer = 21
Third integer = 23
Step-by-step explanation:
To solve this problem, we will need to set up an equation.
x will be the First integer. Let x+2 be the second integer. x+4 is the third integer. It all adds up to 63, so your equation is:
(x)+(x+2)+(x+4)=63
Then solve for x.
x=19
Hope this helps!
-kiniwih426