Which equation is a line that is perpendicular to the line of 8x = −1? A. −x = 8 B. 8y = −1 C. x = −8 D. −8x = −8y

Answer 1

The line given by

8x = -1

is a vertical line, i.e. a line of constant x:

8x = -1 ⇒ x = -1/8 = constant

Therefore, any line of constant y (i.e. a horizontal line) is perpendicular to this line. Only (B) represents a line of constant y.

Answer 2

8x = -1 ---> x = -1/8 which is a vertical line at x=-1/8

the perpendicular is a horizontal line..............

so options A and C are eliminated

option D: x=y upon dividing by -8 which is the identity line, NOT a horizontal line.

option B is a horizontal line y = -1/8 which is perpendicular