# How do you solve by substitution y - 2x = 8 and 16 + 4x = 2y?

Jun 6, 2015

Add $2 x$ to both sides of the first equation to get:

$y = 8 + 2 x$

Divide both sides of the second equation by $2$ to get:

$y = 8 + 2 x$

The two equations determine the same conditions on $x$ and $y$ so this system of equations has an infinite number of solutions, namely all points on the line:

$y = 2 x + 8$