perpendicular lines

Question

Which choice could be the equation of a line perpendicular to the line represented by this equation?

y = 5x− 2

A.
B. y = 5x +2
C.
D. y = −5x + 5

Answer 1

What about A and C?

Perpendicular lines have opposite (i.e., negative vs. positive) and reciprocal slopes.

 

So if a line has a slope of 5, a line perpendicular to it will have a slope of -1/5. Neither of the choices you show have that slope.