Erica has $12 credit on her Cel-Tel phone card. It costs her $1 to make a phone call using her Cel-Tel card. Erica also has $15 credit on her MTT phone card. It costs her $2 to make a phone call using her MTT card. Which system of equations can be solved to find the number of calls, x, that Erica can make and have the same amount of money, y, on both phone cards?


yy==−2x+15−x+12
y = - 2 x + 15 y = - x + 12

yy==2x+15−x+15
y = 2 x + 15 y = - x + 15

yy==−2x−15−x−12
y = - 2 x - 15 y = - x - 12

yy==15x−212x−1
y = 15 x - 2 y = 12 x - 1

Answer:

5 feet

Step-by-step explanation:

Using pythagoras' theorem a^2 = b^2 + c^2

13^2 = 12^2 + c^2

c^2 = 25

c = 5 feet

Answer:5

Step-by-step explanation:

e: x10+x15+x30=3

⇒3x+2x+x30=30

∴x=15

a: 1.5t+2.5t+3.5t=70+0.5t

⇒7.5t−0.5t=70

⇒7t=70⇒t=707=10

b: Let the number be x.

Given that, 2x3−x6=10

⇒4x−x6=10

x=20

d: 3x+5>25−x

⇒3x+x>25−5

⇒4x>20⇒x>204⇒x>5.

[tex]f(x) =-3\\\\\implies 3x^3= -3\\\\\implies x^3 = -1\\\\\implies x = \sqrt[3]{-1} ~~\text{or}~~ x= \sqrt[3]{-1} \left(\dfrac{-1 \pm i\sqrt 3}2\right)\\[/tex]

[tex]\text{For x} \in \mathbb{R}, ~\text{the answer is x} = \sqrt[3]{-1} = -1[/tex]

Answer:

20 of them are managers

Step-by-step explanation:

Basically All you gotta do is convert that 5 percent to a decimal, so 5% = 0.05

400 x 0.05 (multiplying it will just increase your answer) and you will get 20

To check it

20/5% or 0.05 = 400

Answer:

155

Step-by-step explanation:

Answer:

what's the question that you need answered?

Step-by-step explanation:

?

Answer:

x=7

Step-by-step explanation:

Hope this helps!

Answer:

total surface area of a cylinder is 471 cm²

Answer:

18/5

Step-by-step explanation:

simple division mm m m k l k obkbono

Answer:

39/10

Step-by-step explanation:

I promise you correct answer ur welcome

Based on the number of families that left and the number in total on that block, the expected number of families gone on the other block is 25 families.

On the first block, the proportion of families that is gone is:

= Number of families gone / Total number of families on block

= 5 / 12

If there are 60 families on a block, the number gone would be:

= Proportion of families gone x Total number of families

= 5/12 x 60

= 25 families

In conclusion, 25 families would be gone

Find out more on proportions at https://brainly.com/question/11570843.

Answer:

The slope of this line is 4/3.

Step-by-step explanation:

(x1, y1) = (10, 2)

(x2, y2) = (19, 14)

First, find the slope using the slope formula:

[tex]m=\frac{y2-y1}{x2-x1}[/tex]

All this is doing is finding the distance between the y-coordinates and dividing it by the distance between the x-coordinates. I marked these two as points 1 and 2 above, so you can plug in all 4 values and solve:

[tex]m=\frac{14-2}{19-10}\\\\m=\frac{12}{9}\\\\m=\frac{4}{3}[/tex]

The slope of this line is 4/3.

Answer:

Abby will earn $510 if she works 60 hours.

Step-by-step explanation:

8 hrs --> $68

1 hr --> 68 × 1/8 = $8.5

So, 60 hrs

= 8.5 × 60

= $510

Answer:

the nominator could be any number here

Step-by-step explanation:

what do you need ? the equation itself is true, if you put the same number in both places above 21.

any number is possible there, it will not change the equation.

so, again, I am not sure, what you need here.

let's write it with a variable to make my statements clearer :

9 + 1 x/21 = 10 x/21

that is true, because we can combine the whole numbers first giving us 9 + 1 = 10.

and then we add the fraction again (x/21).

again, you can put any number instead of x, and it will always be true.

example

9 + 1 4/21 = 10 4/21

Answer:

.8x dollars

Step-by-step explanation:

Twenty percent off means you are paying 80 percent of every dollar, and 80 percent translates to .8 to 1 as a proportion.

Answer:

$.80x

Step-by-step explanation:

0.80x

Step-by-step explanation:

As it's a product, just multiply each number! We notice there are 2 identical square roots multiplied, and we know that: [tex]\sqrt{x} * \sqrt{x} = x\\[/tex].

So we'll remain with: 5 * 2 * 3 = 30.

:)

Answer:

30

Step-by-step explanation:

First multiply 2 square root with 2 square root and since they are identical the answer will be 2.

Now multiply 3 and 5:

3×5= 15

Now we have two numbers 15 and 2, we will multiply 15 with 2 and we get 30

I couldn't explain well but I hope you understand

Answer:

see explanation

Step-by-step explanation:

(1)

y varies directly as x² then the equation relating them is

y = kx² ← k is the constant of variation

To find k use the condition y = 32 when x = 2

32 = k × 2² = 4k ( divide both sides by 4 )

8 = k

y = 8x² ← equation of variation

When x = 5 , then

y = 8 × 5² = 8 × 25 = 200

(2)

Given F varies inversely as d² then the equation relating them is

F = [tex]\frac{k}{d^2}[/tex] ← k is the constant of variation

To find k use the condition F = 18 when d = 10

18 = [tex]\frac{k}{10^2}[/tex] = [tex]\frac{k}{100}[/tex] ( multiply both sides by 100 )

1800 = k

F = [tex]\frac{1800}{d^2}[/tex] ← equation of variation

When d = 15 , then

F = [tex]\frac{1800}{15^2}[/tex] = [tex]\frac{1800}{225}[/tex] = 8

(3)

y varies jointly as x and z then the equation relating them is

y = kxz ← k is the constant of variation

when x = 3, y = 6, z = 9 ,then

y = 6 × 3 × 9 = 162

Answer: Each phone case costs $6.54.

Explanation:

$32.70 ÷ 5 = cost per cell phone

$32.70 ÷ 5 = $6.54

Answer:

A. No, it does not represent a proportional relationship.

B. Yes, it represents a proportional relationship.

C. No, it does not represent a proportional relationship.

Step-by-step explanation:

think of the increase for X and Y, if they increase at the same rate for both and and for X to Y, they have a proportional relationship.

Answer:

$750

Step-by-step explanation:

did the problem

Answer:

x = 3

Step-by-step explanation:

2x - 3y - z = 7 (equation 1)

3x + 5y - 3z = -2 (equation 2)

4x – y + 2z = 17 (equation 3)

(1) * 3 : 6x - 9y - 3z = 21 (1)'

(1)' - (2) :  3x - 14 y = 23 (equation 4)

(1) * 2 : 4x - 6y - 2z = 14 (1)"

(1)" + (3) : 8x - 7y = 31 (equation 5)

(5)*2 : 16x - 14y = 62 (5)'

(5)' - (4) : 13x = 39

              x = 3

So thus, x = 3 in this system of equations, you can plug x back into equation 4 or 5 to find y and then plug x and y back into equations 1, 2, or 3 to find z

Answer:

x=5

Step-by-step explanation:

First you combine the like terms. next you add 7+23. After that you subtract 10 from both sides. You're left with 4x=20. divide the equation by 4 on each term. Then you're left with x=5.

Answer:

2 units up and 4 units to the right.

Step-by-step explanation:

It is 2 units up and 4 units to the right because since the x-coordinate is positive, that means the point is to the right of the origin and since the y-coordinate is positive, that means the point is above the origin.

Answer:

K so we want to find angle EFC

Its a much longer process

AC is a line, so its 180 degrees

ED is 32 (This also makes AB 32 degrees)

Now we need DC

Find the other side angle length

180 - 32 - 87 = 61

theta is 61+32

Answer:

i think n = 4

Step-by-step explanation:

3(n+7) = 33

3n+21 = 33

3n = 12

n = 4

Answer:

n=4

Step-by-step explanation:

3(n+7)=33

3n + 21=33

3n=33-21

3n=12

n=12÷3

n=4

Answer: what? What’s the question?

Answer:

21.8

Step-by-step explanation:

Answer:

Point A

Step-by-step explanation:

Look along the x axis (horizontal) and find -1. Then look on the y axis and find 1 and 1/4. Finally, find where the two coordinates meet and that's your point - A.

Hope this helps!