Determine whether the graphs of the equations are parallel p

Determine whether the graphs of the equations are parallel, perpendicular, or neither. x + 2y = 8 -2x + y = 8 2x + 5y = 2 y - 2x = 4

x + 2y = 8

divide by 2:

y = -x/2 +4

slope , m1 = -1/2 ;

-2x + y = 8

y = 2x +8

slope, m 2= 2

The slopes are such that m1*m2 = -1

Line are perpendicular

b) 2x +5y = 2

5y = -2x +2

divide the whole equation by 2:

y = -2x/5 +2/5

slope m1 = -2/5

y - 2x = 4

y = 2x +4

slope m2 = 2

The slope are neither equal nor m1*m2 =-1

So, lines are neither parallel nor perpendicualr