Question

Are the graph `y=-3x+7` and `y=-3x+2` perpendicular?

Answer 1

No.

Explanation:

The formula for the slopes of perpendicular lines is

`m_1 * m_2 =-1`

That means that the first gradient times the second gradient should equal `-1`. In this question

`-3 * (-3) = 9`

so they are not perpendicular.