Question

What is the slope of any line perpendicular to the line passing through `(-3,9)` and `(5,-1)`?

Answer 1

`+4/5`

Explanation:

Let the gradient of the first line be `m`

`m=("change in y")/("change in x") =(-1-9)/(5-(-3)) = -10/8=-5/4`

The new line gradient is `-1/m = +4/5`