How do you solve x - y = 11 and x + y = 1 using substitution?

Apr 10, 2018

$\therefore x = 6 \text{ and } y = - 5$

Explanation:

Rearrange first equation

$x - y = 11$

$\implies x = 11 + y$

Substitute this into the second equation...

$\implies \left(11 + y\right) + y = 1$

$\implies 11 + 2 y = 1$

$\implies 2 y = - 10$

=>color(red)( y = -5

We know $x = 11 + y$

$\implies x = 11 + \left(- 5\right)$

=> color(red)(x = 6

color(blue)(therefore x = 6 " and " y = -5