algebra
posted by dennis .
determine which two represent perpendicular lines; y=6x3,y=1/6x+3, y=1/6+3, or y=1/6x3.

To be perpendicular, one equation must have a slope that is the negative of the reciprocal of the other. The slope of the first one is 6, the second is 1/6, the third is 1/6, the fourth is 1/6.