Question 84357
Determine whether each pair of lines is parallel, perpendicular, or neither.

5x-y=8    and    5y= -x+3
If lines are parallel, they have the same slopes. m1=m2
If lines are perpendicular, they have slopes that are negative reciprocals of each other. m1=-1/m2
If the slopes are equal or negative reciprocals they are neither parallel nor perpendicular.
:
To find the slope of an equation of a line, put the equation in slope intercept form: y=mx+b m=slope.
5x-y=8
-5x+5x-y=-5x+8
-y=-5x+8
-(-y)=-(-5x+8)
y=5x-8  the slope of this line is m=5 or m=5/1
5y=-x+3
5y/5=-x/5+3/5
y=(-1/5)x+3/5  the slope of this line is m=-1/5
The slopes of the lines are negative reciprocals of each other (opposite signs and upside down), therefore the lines are perpendicular.
Happy Calculating!!!