Straight Line Graphs summary

Key learning points

• Form $y=mx+c$; also $ax+by+c=0$ rearranged.
• Find equations from two points or a point and gradient.
• Horizontal lines $y=k$; vertical $x=k$ (undefined gradient).

Worked example 1 — Equation from gradient and point

Gradient $2$, through $(0,3)$. Equation?

Working

$y=mx+c$.

Worked example 2 — Parallel

Parallel to $y=3x-1$ through $(0,5)$?

Working

Same gradient.

Worked example 3 — From two points

Points $(0,1)$ and $(2,7)$. Equation?

Working

Find $m$, then $c$.

Scaffolded Learning Sheet and answers (PDFs)

This page is a short, searchable overview for revision and search engines. Use the Scaffolded Learning Sheet first, then the Answers PDF for a full written solution. The printable PDFs remain the main classroom resource.