Question

Question 5

If the following points are from a direct variation, find the missing value.
(-3, y) and (-18, 12)

Answer 1

The missing value is 2

Explanation:

A direct variation satisfies the equation
`y=kx`.

Since the point (-18, 12) lies on this line, it must satisfy this equation.

`\implies 12=-18k`

`k=-(12)/(18) =-(2)/(3)`

Hence the equation of this line is
`y=-(2)/(3)x`

Now we substitute x=-3 to find y.

`y=-(2)/(3)*-3=2`

Therefore the missing value is 2