Question

7

Answer 1

Answer:

Plan A equation:   y = 10x + 30

Plan B equation:  y = x + 80

Plan C equation: y = 5x + 50

Plan A costs the same as Plan C in 4 months

Plan A is the better option if you use 0 - 4 GBs of data each month

Plan B becomes the better deal when 8 months pass

Step-by-step explanation:

When does Plan A cost the same as Plan C?

Set the equations equal to each other (the cost) and solve for x (time in months)

10x + 30 = 5x + 50

5x = 20

x = 4 months

Which plan is best if you only use 0-4 GBs of data a month?

Test the maximum and minimum values to check which plan costs less

At 0 GBs of data used per month

Plan A:  y = 0 + $ 30 = $30 total

Plan B: y = 0 +$80 = $80 total

Plan C: y = 0 + $50 = $50 total

At 4 GBs of data used per month

Plan A: y = $ 40 + $ 30 = $ 70

Plan B: y = $ 4 + $ 80 = $ 84

Plan C: y = $ 20 + $ 50 = $ 70

Comparing the plans at maximum and minimum amount of GBs used, only one plan has the lowest cost overall. Even though Plan C is the same price at 4 GBs as Plan A, when you use 0 GBs you will end up paying more in Plan C than Plan A. Therefore, Plan A is the better option

When does Plan B become the best deal?

When you plot the different Plans on a graph, the slope intercept of x = 7.5 (rounded up to 8) yields the lowest cost for plan B