# How do you solve x = y - 1 and y = 4 - 2x?

May 5, 2018

$y = 2$
$x = 1$

#### Explanation:

$x = y - 1$ --- (1)
$y = 4 - 2 x$ --- (2)

Sub (1) into (2)

$y = 4 - 2 \left(y - 1\right)$
$y = 4 - 2 y + 2$
$3 y = 6$
$y = 2$ --- (3)

Sub (3) into (1)
$x = y - 1$
$x = 2 - 1$
$x = 1$