# Are the graph y=5x+5 and  y=10x+5 perpendicular?

Apr 17, 2016

No

#### Explanation:

Perpendicular lines have a slope that is the opposite (or negative) reciprocal of the other. For example the perpendicular line of $y = 2 x$ would be $y = - \frac{1}{2} x$.

I have graphed $y = 2 x$ and $y = - \frac{1}{2} x$. These two lines are perpendicular to each other.

In this case, it's basically that if you multiply 5 by 2, then you would get 10 (which is the second equation's slope).

Notice the lines are not perpendicular. Instead they intersect at the point (0,5)