Question

c(x)=200+.4x find c(x+1)-c(x)

Answer 1

what's the trouble?

c(x+1) = 200 + .4(x+1) = 200 + .4x + .4 = 200.4 + .4x

c(x+1)-c(x) = 200.4 + .4x - (200 + .4x) = 0.4