Lines have many equation forms — pick the one that matches what you know.
Three common forms
- Slope-intercept: y = mx + b — m is slope, b is y-intercept.
- Point-slope: y − y₁ = m(x − x₁) — slope and one point.
- Two-point: m = (y₂ − y₁)/(x₂ − x₁) — derive slope first.
Try it
Line through (1, 2) with slope 3
y − 2 = 3(x − 1) → y = 3x − 1.