Question

1. What is the constant of variation for the relationship f(x) = 40x?

2. Which equation is the direct variation equation if f(x) varies directly with x and f(x) = -12 when x=6

Answer 1

1. The coefficient of x is the constant of variation. It is 40.

2. -12 = -2*6 . . . . . you know this because you know your times tables
.. f(x) = -2x