How do you solve $4x-4y=-16$ and $x-2y=-12$ using substitution?

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Answer 1 · 2016-03-08T05:57:01

$x=4$
$y=8$

Given -

$4x-4y=-16$ ----------------------(1)
$x-2y=-12$ -------------------------(2)

Solve equation (2) for

$x-2y=-12$
$x=-12+2y$

Substitute > $x=-12+2y$ in equation (1)

$4(-12+2y)-4y=-16$
$-48+8y-4y=-16$
$4y=-16+48=32$
$y=32/4=8$
$y=8$

Substitute $y=8$ in equation (2)

$x-2(8)=-12$
$x-16=-12$
$x=-12+16=4$
$x=4$

How do you solve 4x-4y=-164x-4y=-16 and x-2y=-12x-2y=-12 using substitution?