Question

In a direct variation, y is -18 when x is 9. What is y when x equals -6?

A.-12

B.-3

C.3

D.12

Answer 1

@skullpatrol @iambatman

Answer 2

\(\large\color{midnightblue}{ y=kx }\) is the equation of the direct variation, where `k` is a constant.

You are given that, `y=-18` and `x=9`. Solve for `k`.
\(\large\color{midnightblue}{ y=kx }\)
\(\large\color{midnightblue}{ -18=k(9) }\)
\(\large\color{midnightblue}{ -2=k }\)

Answer 3

\(\large\color{midnightblue}{ y=(-2)x }\)
So, when x=6... say \(\large\color{midnightblue}{ y=(-2)(-6) }\)
\(\large\color{midnightblue}{ y=? }\)