JAMB 2012 · UTME · Q34

Find the equation of the line through the points $(-2, 1)$ and $\left(-\frac12, 4\right)$ .

Worked solution (try it first)

Gradient: the change in $y$ is $4 - 1 = 3$ and the change in $x$ is $-\frac12 - (-2) = \frac32$ , so $m = 3 \div \frac32 = 2$ .
Through $(-2, 1)$ : $y - 1 = 2(x - (-2))$ , so $y - 1 = 2x + 4$ .
So $y = 2x + 5$ , option B.