Question

A line containing the points (4,1) and (0,0) intersects a line containing (1,0) and (-1,y). If the lines are perpendicular, what is the value of y?

Answer 1

(-1,-8)

Explanation:

the first line has a slope of 1-0/4-0 = 1/4

and a perpendicular slope should have different sign and the fraction flipped which means we need to find a slope of -4 for the perpendicular line

0-y/1-(-1)=-4

-y/-2=-4

y=-8