Question 224177
The slopes of two lines are the negative reciprocal of eath other for example: y=2x and y = -1/2x 
What must be true about the two lines?
They're perpendicular.
-------------------
Is the conjecture true if the y-intercept of either equation is not zero? 
The y-intercept is irrelevant.  Only the slopes determine that they're perpendicular.
explain