Question

Which of the following pairs of lines are perpendicular? Select all that apply.

Answer 1

y =
`(4)/(5) x` - 8

y = -
`(5x)/(4)` + 3

y =
`(2)/(3) x` - 8

y =
`(-3)/(2)x - 8`

Explanation:

To know the pairs that are perpendicular lines, we need to understand what makes a line perpendicular to another.

Perpendicular lines generally have slopes;

m and
`-(1)/(m)`

So, any of the pairs with a negative inverse value of slope will be perpendicular.

y =
`(4)/(5) x` - 8 slope =
`(4)/(5)`

y =
`-(5x)/(4) + 3` slope =
`-(5)/(4)`

We see they are negative inverses

y =
`(2)/(3) x` - 8 slope =
`(2)/(3)`

y =
`(-3)/(2)x - 8` slope =
`-(3)/(2)`

These are also negative inverses.