Question

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

Answer 1

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

`y = 8 + 2x`

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

`y = 8 + 2x`

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 = 2x + 8`