Question

Under her cell phone plan, Julieta pays a flat cost of $61.50 per month and $5 per gigabyte. She wants to keep her bill at $78 per month. Write and solve an equation which can be used to determine gg, the number of gigabytes of data Julieta can use while staying within her budget.

Answer 1

3 gigabytes

Explanation:

Let x = gigabyte

Since she pays $5 per gigabyte, multiply x by 5 like this: 5x

There is also a flat cost of $61.50, so add 61.5 to it like this: 5x + 61.5

If Julieta wants to find the max amount of gigabytes she can use while staying under the $78 range, set the equation equal to 78.

5x + 61.5 = 78

Subtract 61.5 from both sides

5x + 61.5 = 78

- 61.5 - 61.5

5x = 16.5

Divide both sides by 5 to isolate the x variable

5x/5 = 16.5/5

x = 3.3

I'm assuming that if she uses more than 3 gigabytes, the plan will charge her the same price as if she is using 4 gigabytes.