Question

Which is the direct linear variation equation for the relationship given y varies directly with x and y = 12 when x = 3?

Answer 1

`y=4x`

Explanation:

For a direct linear variation equation
`color(white)("XXX")y=k*x` for some constant `k`

Given `y=12` when `x=3`
we have
`color(white)("XXX")12=k*3`

`rArr k=4`

and the equation is
`color(white)("XXX")y=4x`