How do you solve the system $x+2y=13$ and $-2x-3y=-18$ using substitution?

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Answer 1 · 2017-08-04T05:56:33

$y=8$
$x=-3$

Given -

$x+2y=13$ ------------------- (1)
$-2x-3y=-18$ -------------------(2)

Solve equation (1) for $x$

$x=13-2y$

Substitute $x=13-2y$ in equation (2)

$-2(13-2y)-3y=-18$
Simplify
$-26+4y-3y=-18$
$y=-18+26=8$

$y=8$

Substitute $y=8$ in equation (1)

$x+2(8)=13$
$x+16=13$
$x=13-16=-3$
$x=-3$

How do you solve the system x+2y=13x+2y=13 and -2x-3y=-18-2x-3y=-18 using substitution?