90,000,000 is the answer
Step-by-step explanation:
Part A: c for cost. c=0.31m+0.5
0.31m is the cost per minute. 0.5 is cost per call.
Part B: 0.31m+0.5=5.15 to solve we must rearrange.
subtract 0.5 from each side giving us 0.31m=4.85
divide by 0.31 giving us m=15.65
The answer is number 4. Cube
Original price = x
x - .2x = 200 ← original price - discount amount = sale price
.8x = 200 ← 1x - 0.2x = .8x
x = 250 ← divided both sides by .8
The original price was $250
