How do you solve $2x+3y=9$ and $2x+y=11$ using substitution?

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Answer 1 · 2016-03-12T10:21:52

The quickest way would be to subtract the second equation from the first

We have $2x+3y=9$
minus $2x+y=11$
leaves $cancel(2x)-cancel(2x)+3y-y=9-11$
$2y=-2->y=-1$
Now substitute that for $y$ :
$2x+ (-1)=11->2x=12->x=6$

Check with the other equation:
$2xx6+3xx(-1)=12-3=9$ check!

How do you solve 2x+3y=92x+3y=9 and 2x+y=112x+y=11 using substitution?