11.3 Finding the equation of a line — Practise

Work independently in order. The later questions mix this section with earlier methods. Questions marked H are Higher only.

1. Find the equation of a line through the origin with gradient 5.
2. Find the equation with gradient 2 through $(0,4)$.
3. A line has gradient -3 and passes through $(2,1)$. Find its equation.
4. A line $y=mx+2$ passes through $(3,11)$. Find $m$.
5. Find the equation of the line through $(0,-2)$ and $(4,6)$.
6. Find the equation of a line with gradient 4 through $(1,7)$.
7. A line has values $(1,5),(2,8),(3,11)$. Find its equation.
8. A taxi fare is £4 plus £2.50 per kilometre. Write the cost $C$ for $d$ kilometres.
9. Which method finds a line equation from two points: use the gradient then substitute, or read an intercept? Give the gradient for $(2,1),(6,9)$.
10. H Find the equation through $(-2,5)$ and $(4,-4)$.