Question

Write an equation of the direct variation that includes the point (9, -12).

Answer 1

`y=-(4)/(3)x`

Explanation:

we know that

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
`y/x=k` or
`y=kx`

step 1

Find the value of k

we have

the point (9,-12)

x=9, y=-12

`k=y/x`

substitute

`k=-12/9=-4/3`

step 2

Find the equation

`y=kx`

so

`y=-(4)/(3)x`