# Math Help - Find point of intersection

1. ## Find point of intersection

How do you find the point of intersection of lines without graphing?

Ex.
$y=2x+3 \ \ \ y=-\frac{1}{2}x-1$

2. Replace y in the second equation:

$2x+3=-\frac{1}{2}x-1\Rightarrow 2x+\frac{1}{2}x=-4\Rightarrow\frac{5}{2}x=-4\Rightarrow x=-4\cdot\frac{2}{5}=-\frac{8}{5}$

Now find y.

3. The intersection of two lines = the system's solutions.

Use any of the methods to solve a system of equations.