So we can see that the equation has a slope and a y-intercept .
Now move onto the second equation.
Rearrange the terms.
Divide both sides by to isolate y.
Break up the fraction.
Reduce.
So we can see that the equation has a slope and a y-intercept .
So the slope of the first line is and the slope of the second line is .
Notice how the slope of the second line is simply the negative reciprocal of the slope of the first line .
In other words, if you flip the fraction of the second slope and change its sign, you'll get the first slope. So this means that the graphs of and are perpendicular lines.