WAEC 2022 · Paper 1 · Q46

The straight line $y = mx - 4$ passes through the point $(-4, 16)$ . Calculate the gradient of the line.

Worked solution (try it first)

The point is on the line, so put $x = -4$ and $y = 16$ into $y = mx - 4$ : $16 = -4m - 4$ .
Add 4 to both sides: $20 = -4m$ .
Divide by $-4$ : $m = -5$ , option A.