Question

Is the line y = 3x - 7 parallel or perpendicular to 3x + 9y

= 9? Explain your answer.

Answer 1

Perpendicular

Explanation:

Simplify 3x+9y=9 to 9y=-3x+9 and then to y=-1/3x+1

y=3x-7

and

y=-1/3x+1, 3 and -1/3 are negative reciprocals which makes these equations perpendicular.