Question

In the equation below, determine whether y varies directly with x. If so, find the constant of variation k.

3y = –7x – 18

Answer 1

No, y does not vary directly with x.

Explanation:

3y = -7x - 18 Write the original equation.

`(3y)/(3) = (-7x-18)/(3)` Divide both sides by 3 to isolate y, then simplify.

y =
`-(7)/(3)x -6`

Since the equation can not be written as y=kx, y DOES NOT vary directly with x.

Answer 2

we are given the equation 3y = -7x - 18 and is asked whether y is directly proportional to x and if it is, we find the constant of variation. In this case, we simplify the equation into y = -7/3 x -6. In this case, we can see that y is proportional to x with a constant of proportionality of -7/3