Expert: Richard J. Raridon - 4/20/2007

Question
2x-y=12
y=-1/2x-6

this problem would be perpendicular but I dont get how its perpendicular....
Please help me I'm so confused  

Answer
the standard equation for a straight line is y=mx+b where m is the slope and b is the y-intercept.  
so the slope for y=(-1/2)x -6 is -1/2.
if you rewrite the first eq. you get y = 2x-12 and the slope is 2.  these lines are perpendicular since the slope of one is the negative reciprocal of the other.