Answer:
Consider all the info you are given:
The monthly allowance is 2 GB...this is basically how much data is included in the the plan so that the monthly pymt is the same every month. When the GBs used goes pass 2GB...there is a cost to that.
You're given C(x) = 30x + 50, the monthly cost of the plan
'x' is the GB of data used OVER the allowance (2GB.)
They put over in italics to give you a hint to the solution.
(a) C(0.7) is the cost when the data used goes over 2GB by 0.7 GB. C(0.7) = 30(0.7) + 5 = 26
The college student would pay $26 when they use an extra 0.7GBs (pass the allowance.)
(b) This part to the problem wants you to figure out how much the overage, pass the 2GBs, the college student can go and only end up paying $50 (the set budget)
So you the solve for x by setting C(x) = 50
30x + 5 = 50
30x = 50 - 5 = 45
x = 45/30
x = 1.5
Remember x is the overage (the GBs over the allowances), so to stay at budget, the college student can use 3.5 GBs of data (2GBs + 1.5 GBs) only pay $50 that month.
Hope this helps...
