Answer:
y = -
x
Explanation:
the equation of a line passing through the origin is
y = mx ( m is the slope of the line )
calculate m using the slope formula
m =

with (x₁, y₁ ) = (- 8, 4) and (x₂, y₂ ) = (0, 0) ← 2 points on the line
m =
=
=
= -
, then
y = -
x ← equation of line