Bob went out to dinner and paid a 15% tip on a $20 meal? How much is the total bill?

Answer:

Expand  [tex]-3(9-x): -27 + 3x[/tex]

Step-by-step explanation:

[tex]-3(9-x)[/tex]

Apply the distributive law: [tex]a(b-c)=ab-ac[/tex]

[tex]a = -3, b=9, c=x[/tex]

[tex]=-3*9-(-3)x[/tex]

Apply minus - plus rules:

[tex]-(-a)=a[/tex]

[tex]= -3*9+3x[/tex]

Multiply the numbers: [tex]3 * 9 = 27[/tex]

[tex]=-27+3x[/tex]

Hope this helps! If so, may I get Brainliest and a Thanks?

Thank you, have a good one! =)

Answer:

Nah ;)

Step-by-step explanation:

Answer: A

Step-by-step explanation:

2x + 9 = 15

2x = 6

x = 3

2x+9 = -15

2x = -24

x = -12

Answer:

C≈402.12in

Step-by-step explanation:

The circumference of a circle is equal to pi times the diameter. The diameter is two times the radius, so the equation for the circumference of a circle using the radius is two times pi times the radius

Answer:

[tex]d = \sqrt{29}[/tex]

General Formulas and Concepts:

Pre-Algebra

Algebra II

Step-by-step explanation:

Step 1: Define

Point (8, -3)

Point (6, -8)

Step 2: Find distance d

Answer:

1:4

Step-by-step explanation:

1 would be the teachers

times 4 would be the students

Answer:   1:4 or 2:16

It can be either answer because the ratios are multiplied with that but it can be divided enough to be 1:4 so any answer would be right if you multiply the ratio by 4

Answer:

i need help on this question too

Step-by-step explanation:

Answer:

I think X=10 but im not for sure.

Step-by-step explanation:

150 (X+10) = 200 (X+5)

150x+1500   200X+1000

-150X            -150X

1500               50X+1000

-1000                      -1000

500                50X

50                   50

10=X

Answer:

6x^2+10x-6=0

Step-by-step explanation:

First, you need to add all like terms:

6x^2+8x-6=-2x

Now move the -2x to the other side:

6x^2+10x-6=0

Answer:

x =(-5+√61)/6= 0.468

or:

x =(-5-√61)/6=-2.135

Step-by-step explanation:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

                    6*x^2+8*x-6-(2-2*x-2)=0  

Step by step solution :

STEP 1 :

The Equation at the end of step 1

 (((2•3x2) +  8x) -  6) -  -2x  = 0  

STEP 2 :

STEP 3 :

Pulling out like terms

3.1     Pull out like factors :

  6x2 + 10x - 6  =   2 • (3x2 + 5x - 3)  

Trying to factor by splitting the middle term

3.2     Factoring  3x2 + 5x - 3  

The first term is,  3x2  its coefficient is  3.

The middle term is,  +5x  its coefficient is  5.

The last term, "the constant", is  -3  

Step-1: Multiply the coefficient of the first term by the constant   3 • -3 = -9  

Step-2: Find two factors of  -9  whose sum equals the coefficient of the middle term, which is   5.

     -9    +    1    =    -8  

     -3    +    3    =    0  

     -1    +    9    =    8  

Observation: No two such factors can be found !!

Conclusion: Trinomial can not be factored

The Equation at the end of step 3 :

 2 • (3x2 + 5x - 3)  = 0  

STEP 4 :

Equations which are never true:

4.1      Solve :    2   =  0

This equation has no solution.

A non-zero constant never equals zero.

Parabola, Finding the Vertex:

4.2      Find the Vertex of y = 3x2+5x-3

Parabolas have the highest or lowest point called the Vertex.   Our parabola opens up and accordingly has the lowest point (AKA absolute minimum).   We know this even before plotting  "y"  because the coefficient of the first term, 3, is positive (greater than zero).  

Each parabola has a vertical line of symmetry that passes through its vertex. Because of this symmetry, the line of symmetry would, for example, pass through the midpoint of the two x-intercepts (roots or solutions) of the parabola. That is if the parabola has indeed two real solutions.  

Parabolas can model many real-life situations, such as the height above ground, of an object thrown upward, after some period of time. The vertex of the parabola can provide us with information, such as the maximum height that an object, thrown upwards, can reach. For this reason, we want to be able to find the coordinates of the vertex.  

For any parabola, Ax2+Bx+C, the x -coordinate of the vertex is given by  -B/(2A). In our case, the  x  coordinate is  -0.8333  

Plugging into the parabola formula  -0.8333  for  x  we can calculate the  y -coordinate :  

 y = 3.0 * -0.83 * -0.83 + 5.0 * -0.83 - 3.0

or   y = -5.083

Parabola, Graphing Vertex, and X-Intercepts :

Root plot for :  y = 3x2+5x-3

Axis of Symmetry (dashed)  {x}={-0.83}  

Vertex at  {x,y} = {-0.83,-5.08}  

x -Intercepts (Roots) :

Root 1 at  {x,y} = {-2.14, 0.00}  

Root 2 at  {x,y} = { 0.47, 0.00}  

Solve Quadratic Equation by Completing The Square

4.3     Solving   3x2+5x-3 = 0 by Completing The Square.

Divide both sides of the equation by  3  to have 1 as the coefficient of the first term :

  x2+(5/3)x-1 = 0

Add  1  to both side of the equation :

  x2+(5/3)x = 1

Now the clever bit: Take the coefficient of  x, which is  5/3, divide by two, giving  5/6, and finally square it giving  25/36  

Add  25/36  to both sides of the equation :

 On the right-hand side we have :

  1  +  25/36    or,  (1/1)+(25/36)  

 The common denominator of the two fractions is  36   Adding  (36/36)+(25/36)  gives  61/36  

 So adding to both sides we finally get :

  x2+(5/3)x+(25/36) = 61/36

Adding  25/36  has completed the left-hand side into a perfect square :

  x2+(5/3)x+(25/36)  =

  (x+(5/6)) • (x+(5/6))  =

 (x+(5/6))2

Things which are equal to the same thing are also equal to one another. Since

  x2+(5/3)x+(25/36) = 61/36 and

  x2+(5/3)x+(25/36) = (x+(5/6))2

then, according to the law of transitivity,

  (x+(5/6))2 = 61/36

We'll refer to this Equation as  Eq. #4.3.1  

The Square Root Principle says that When two things are equal, their square roots are equal.

Note that the square root of

  (x+(5/6))2   is

  (x+(5/6))2/2 =

 (x+(5/6))1 =

  x+(5/6)

Now, applying the Square Root Principle to  Eq. #4.3.1  we get:

  x+(5/6) = √ 61/36

Subtract  5/6  from both sides to obtain:

  x = -5/6 + √ 61/36

Since a square root has two values, one positive and the other negative

  x2 + (5/3)x - 1 = 0

  has two solutions:

 x = -5/6 + √ 61/36

  or

 x = -5/6 - √ 61/36

Note that  √ 61/36 can be written as

 √ 61  / √ 36   which is √ 61  / 6

Solve Quadratic Equation using the Quadratic Formula

4.4     Solving    3x2+5x-3 = 0 by the Quadratic Formula.

According to the Quadratic Formula,  x, the solution for   Ax2+Bx+C  = 0, where  A, B,  and  C are numbers, often called coefficients, is given by :

           - B  ±  √ B2-4AC

 x =   ————————

                     2A

 In our case,  A   =     3

                     B   =    5

                     C   =   -3

Accordingly,  B2  -  4AC   =

                    25 - (-36) =

                    61

Applying the quadratic formula :

              -5 ± √ 61

  x  =    —————

                   6

 √ 61, rounded to 4 decimal digits, is   7.8102

So now we are looking at:

          x  =  ( -5 ±  7.810 ) / 6

Two real solutions:

x =(-5+√61)/6= 0.468

or:

x =(-5-√61)/6=-2.135

HOPE THIS HELPS!

PLEASE MARK BRAINLIEST IF THIS HELPED YOU LEARN! :)

Answer:

17.32 cm

6.21 cm

Step-by-step explanation:

a^2+b^2=c^2

a^2+22^2=28^2

a^2=300

6^2+4^2=c^2

c=6.21

Hopefully this helps!

Answer:

1/3 or 33.33333333%

Step-by-step explanation:

The chance of getting a head in the coin flip is 1/2 or 50%.

The chance of getting a number bigger than 2 (3,4,5,6) is 4/6 or 2/3 or 66.6666666666%. (There are a total of four possibilites in six.)

Hence, 50% * 2/3 = 33.333333333333%.

Hope this helped!

Answer:

see explanation

Step-by-step explanation:

Parallel lines have equal slopes.

To find D and E use the midpoint formula

Given endpoints (x₁, y₁ ) and (x₂, y₂ ) then the midpoint is

( [tex]\frac{x_{1}+x_{2} }{2}[/tex], [tex]\frac{y_{1}+y_{2} }{2}[/tex] )

Here (x₁, y₁ ) = A(4, 6) and (x₂, y₂ ) = B(2, - 2) , then

D = ([tex]\frac{4+2}{2}[/tex], [tex]\frac{6-2}{2}[/tex] ) = (3, 2 ) and

let (x₁, y₁ ) = B(2, - 2[tex]\frac{-4+2}{-2-2}[/tex] ) and (x₂, y₂ ) = C(- 2, - 4 ), then

E = ( [tex]\frac{4-2}{2}[/tex], [tex]\frac{6-4}{2}[/tex] ) = (1, 1 )

Use the slope formula to find slopes of DE and BC

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = D(3, 2) and (x₂, y₂ ) = E(1, 1), then

[tex]m_{DE}[/tex] = [tex]\frac{1-2}{1-3}[/tex] = [tex]\frac{-1}{-2}[/tex] = [tex]\frac{1}{2}[/tex]

Repeat with (x₁, y₁ ) = B(2, - 2) and (x₂, y₂ ) = C(- 2, - 4), then

[tex]m_{BC}[/tex] = [tex]\frac{-4+2}{-2-2}[/tex] = [tex]\frac{-2}{-4}[/tex] = [tex]\frac{1}{2}[/tex]

Since the slopes are equal then DE and BC are parallel lines

Answer:

-4/2x+3 or if you simplyfy it will be -2x+3

Step-by-step explanation:

Answer:

[tex]y = -\frac{1}{2}x + 3[/tex]

Answer:

x < 24

Step-by-step explanation:

-1/2x < -12

1) Isolate x!

-1/2x < -12

×-2 ×-2

x < 24

if you add 55% and 45% the total is 100% so 45/100 are girls.  35% of the girls scored and A  so 35/45  is the probability that it is a girl chosen or 7/9. the probability is 7 out of 9.

Answer:

a) 0.04

b) 0.54674

c) 0.10565

d) It is not unusual to have preterm babies

Step-by-step explanation:

The lengths of a particular​ animal's pregnancies are approximately normally​ distributed, with mean, μ = 272 days and standard deviation, σ = 16 days.

We solve the above question using z score formula

z = (x-μ)/σ, where

x is the raw score

μ is the population mean

σ is the population standard deviation.

​(a) What proportion of pregnancies lasts more than 300 ​days?

z = 300 - 272/16

= 1.75

Probability/proportion value from Z-Table:

P(x<300) = 0.95994

P(x>300) = 1 - P(x<300) = 0.040059

Approximately = 0.04

​(b) What proportion of pregnancies lasts between 260 and 284 ​days?

For x = 260 days

z = 260 - 272/16

= -0.75

Probability value from Z-Table:

P(x = 260) = 0.22663

For x = 284

z= 284 - 272/16

= 0.75

Probability value from Z-Table:

P(x = 284) = 0.77337

The proportion of pregnancies lasts between 260 and 284 ​days is

P(x= 284) - P(x = 260)

0.77337 - 0.22663

= 0.54674

​(c) What is the probability that a randomly selected pregnancy lasts no more than 252 ​days?

No more than means less than or equal to, hence, we are to find

P ≤ 252 days

Hence,

z = 252 - 272/16

= -1.25

Probability value from Z-Table:

P(x ≤ 252) = 0.10565

​(d) A​ "very preterm" baby is one whose gestation period is less than 236 days. Are very preterm babies​ unusual?

We find the probability of 236 days

For x = 236

z = 236 - 272/16

z = -2.25

Probability value from Z-Table:

P(x<236) = 0.012224

Converting to percentage = 1.2224%

Hence, it is not unusual to have preterm babies

Answer:

1 / 14

Step-by-step explanation:

4 / 56 = 1 / 14

4 / 4 = 1

56 / 4 = 14

Answer:

0.4% of the people had a mild allergic reaction.

Step-by-step explanation:

You can find the percent of the people that had a mild allergic reaction using a rule of three as you know that 9,000 people tried the new shampoo which would be the 100% and you can find the percent that represents 36 people:

9,000 → 100%

  36    →   x

x=(36*100)/9,000

x=0.4%

According to this, the answer is that 0.4% of the people had a mild allergic reaction.

Answer:

y-intercept=(0, 3)  slope=-2

hope this help

Step-by-step explanation:

Answer: y intercept= 3 slope is -2

Step-by-step explanation: you subtract 2x from the left and right side and end up with y= -2x+3 if you substitute x for 0 then you get 3 for the y intercept.

Answer:

y=x+5/12

good luck...

3x-5y-z+13.

it is simplified all the way there is nothing to add

Answer:

A

Step-by-step explanation:

because a is 139cm and child is 139 cm not 830000 or not 1.48

Answer:

60

Step-by-step explanation:

Answer:

m=2

Step-by-step explanation:

Answer:

[tex]m=2[/tex]

Step-by-step explanation:

[tex]-7+4m+10=15-2m[/tex]

Isolate the variable m. Combine like terms (-7+10):

[tex]3+4m=15-2m[/tex]

Subtract 3 from both sides (inverse operations):

[tex]3-3+4m=15-3-2m\\\\4m=12-2m[/tex]

Add 2m to both sides (inverse operations):

[tex]4m+2m=12-2m+2m\\\\6m=12[/tex]

Divide both sides by 6 to isolate m (inverse operations):

[tex]\frac{6m}{6} =\frac{12}{6} \\\\m=2[/tex]

Since this cannot be further simplified, m is equal to 2.

:Done

Using the probability concept, the correct option regarding who is more likely to brush both in the morning and in the evening is:

B. Arabella. She has a 0.64 probability of brushing both times.

A probability is given by the number of desired outcomes divided by the number of total outcomes.

Considering that the events are independent, we just multiply the probabilities, hence the probability of each brushing both times is given as follows:

Hence statement B is correct, as 0.64 > 0.612.

More can be learned about probabilities at https://brainly.com/question/14398287

#SPJ1

Answer:

sorry I don't know 2...

But first I can tell....

Step-by-step explanation:

circumference = 220m

To Find :- It's diameter and it's radius...

Solution:-

circumference of circle = 2*pi*r

pi=22/7

220 = 2*22/7*r

220 = 44r/7

220*7 = 44r

1540 = 44r

r = 1540/44

r = 35m....

d = 35*2

d = 70m...

Hence, Diameter of circular field is 70m and radius is 35m