The cost of a long-distance phone call is $0.41 for the first minute and $0.30 for each additional minute. If the total charge for a long-distance call is $7.91, how many minutes was the call?
Please help me! Help me find a solution with steps so that I know how to handle a math problem like this in the future. Thanks!
Let number of minutes call lasted, be m
Then number of minutes used, at $0.30 is: m - 1
Therefore, C(m) = .3(m - 1) + .41
C(m) = .3m - .3 + .41
C(m) = .3m + .11
7.91 = .3m + .11 ------- Substituting 7.91 for C(m), or cost
.3m = 7.91 - .11
.3m = 7.8
m, or minutes call lasted = , or