Determine whether the graphs of the given equations are parallel, perpendicular, or neither. Explain.

Question

y=4x+5

-4x+y=-13

Answer 1

Lines are parallel if their slopes are the same, perpendicular if their slopes are negative reciprocals, and neither otherwise. When you lines are in the form y=mx+b, the slope can easily be recognized as the coefficient m.

Solve your second equation for y. Compare the coefficient of x in this equation with m=4 in the first.