Answer:
To stay within budget, she must use 4.5 gigabytes.
Step-by-step explanation:
Giving the following information:
Under her cell phone plan, Sofia pays a flat cost of $58.50 per month and $4 per gigabyte. She wants to keep her bill at $76.50 per month.
<u>First, we need to establish the total cost formula:</u>
Total cost= 58.5 + 4*x
x= number of gigabytes
<u>Now, we isolate x:</u>
76.5= 58.5 + 4x
18/4= x
4.5= x
To stay within budget, she must use 4.5 gigabytes.