Question

How do you find the direct variation equation of the graph through the points (0, 0) and (1, -2)?

Answer 1

A direct variation equation is of the form
`y = mx` for some constant value `m`
(note that all direct variation equations go through `(0,0)` so this is irrelevant information)

We have that the line of the direct variation equation goes through `(x,y)=(1,-2)`
so substituting this back into the general form we get
`-2 = m(1)`
that is
`m=(-2)`
and the direct variation equation is
`y = -2x`