A cellular Phone company offers a contract for which the cost C, in dollars, of T minutes of telephoning is given by C=0.25(t-600)+75.95, where it is retriceumed that t or equal to 600 minutes. What times will keep costs between $120.20 and $147.45?
So far i got:
C=.25(t-600)+75.95=.25t-150+75.95=.25t-74.05
& got
120.20=.25t-75.05, and 147.45=.25t-75.05 but how do i solve it?

Question

A cellular Phone company offers a contract for which the cost C, in dollars, of T minutes of telephoning is given by C=0.25(t-600)+75.95, where it is retriceumed that t > or equal to 600 minutes.  What times will keep costs between $120.20 and $147.45?  
So far i got:
C=.25(t-600)+75.95=.25t-150+75.95=.25t-74.05
& got 
120.20=.25t-75.05, and 147.45=.25t-75.05 but how do i solve it?

anonymous · Answer

you add 75.05 to both sides and then multiply both sides by 4 to find what t is equal to.  Anything between these two t's is your answer

anonymous · Answer

THX i think i got it