Question

The points (-1, 7) and (4,r) lie on a line with slope - 2. Find the missing coordinate r

Answer 1

r = -3

Explanation:

Given:

(x₁, y₁) = (-1, 7)

(x₂, y₂) = (4, r)

m = -2

`\boxed{m=(y_2-y_1)/(x_2-x_1) }`

`-2=(r-7)/(4-(-1))`

`-2=(r-7)/(5)`

`r-7=-2(5)`

`r=-10+7`

`r=-3`