cell phone company Y charges a $10 start up fee plus $0.10 per minute, x. Cell phone company Z charges $0.20 per minute, x, with no start up fee. Which function represents the difference in cost between company Y and company Z?
A.) f(x) = -0.10x-70
B.) f(x) = -0.10x+10
C.) f(x) = 10x-0.10
D.) f(x) = 10x+0.10
A.) f(x) = -0.10x-70
B.) f(x) = -0.10x+10
C.) f(x) = 10x-0.10
D.) f(x) = 10x+0.10