Question

Are these two lines parallel, perpendicular, or neither: `y = -7/8x – 1` and `32x – 28y = -36` ?

Answer 1

Perpendicular.

Explanation:

the first has inclination `-7/8 = a`

the second, `32x + 36 = 28y`

inclination `= 32/28 = 8/7 = - 1/a`

`y = ax + b` is parallel to
`y = ax + c`
and both are perpendicular to `y = -1/a + d`