First of all, we know that it's a linear equation, which means it'll have to be y=mx+b.
Identify your points. (0, 0) and (5, 4).
Now find the slope by doing m = (y₂ - y₁)/(x₂ - x₁) m = (4 - 0)/(5 - 0) m = 4/5 So the slope is 4/5 or 0.8.
Now set the equation up. You have a point and the slope, so use the point-slope equation. y - y₁ = m(x - x₁) y - 4 = 4/5(x - 5) y - 4 = 4/5x - 4 y = 4/5x
