Question 486771
Let c(x) be cost of x copies.
Linear means c(x) = ax + b
c(5) = 80
c(18) = 116
Find c(10)
a*5 + b = 80
a*18 + b = 116
Subtract 1 from 2:
13*a = 36
a = 36/13 = 2.77
2.77*5 + b = 80
b = 80-13.846 = 66.154
c(10) = 10 * 2.77 + 66.15
c(10) = 93.85