Question 155134
If  line p and q are perpendicular to each other, all angles must be equal to 90°.
So
3x + 18 = 90 .................(1)
-8y - 70 = 90 ................(2)
Solving equation (1) for x, we have
3x = 72
x = 24
Solving equation (2) for y, we have
-8y = 160
y = -20