Question

Which choice could be the equation of a line perpendicular to the line represented by this equation? y = 5x− 2

A. y= -1/5x + 5

B. y = 5x + 2

C. y= 1/5x - 7

D. y = -5x + 5

Answer 1

Option A. y= -1/5x + 5

Explanation:

step 1

Find the slope of the given line

we have

y=5x-2

The slope m is

m=5

step 2

Find the slope of a line perpendicular to the given line

Remember that

If two lines are perpendicular, then their slopes are opposite reciprocal (the product of their slopes is -1)

m1*m2=-1

we have

m1=5

(5)*m2=-1

m2=-1/5

therefore

The equation of a line perpendicular to the given line could be

y= -1/5x + 5