How do you solve by substitution $x + 3y = 8$ and $2x - y = 9$ ?

Question

5549 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-07-14T20:22:23

$x=5,y=1$

Solving the first equation for $x$ :
$x=8-3y$
Substituting this ( for $x$ )in the second equation

$2(8-3y)-y=9$

expanding

$16-6y-y=9$

$16-7y=9$
so

$7y=7$ so $y=1$

and

$x=8-3$

$x=5$

How do you solve by substitution x + 3y = 8x + 3y = 8 and 2x - y = 92x - y = 9?