SOLUTION: which of the following represents a lie perpendicular to 9x-3y=7? -81x-3y=7 -81x-27y=7 -3x+9y=7 27x+81y=7

Algebra ->  Linear-equations -> SOLUTION: which of the following represents a lie perpendicular to 9x-3y=7? -81x-3y=7 -81x-27y=7 -3x+9y=7 27x+81y=7      Log On


   

Question 567427: which of the following represents a lie perpendicular to 9x-3y=7?
-81x-3y=7
-81x-27y=7
-3x+9y=7
27x+81y=7
Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
9x-3y=7?

convert to slope intercept form
3y=9x-7
/3
y=3x-7/3
slope = 3
the perpendicular line will have a slope of -1/3 ( negative reciprocal)
...
27x+81y=7
81y=-27x+7
/81
y=(-27/81)x+7/81
y=(-1/3)x+7/81
this line is perpendicular