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

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Answer 1 · 2016-03-21T15:26:29

$x = - 4$ $x=-4$
$y = - 8$ $y=-8$

$y = x - 4$ $y=x-4$
$y = 2 x$ $y=2x$

We know that $y$ $y$ is $2 x$ $2x$ so we replace $y$ $y$ in the first equation with $2 x$ $2x$ .

$2 x = x - 4$ $2x=x-4$
$2 x - x = - 4$ $2x-x=-4$
$x = - 4$ $x=-4$

If $y$ $y$ is $2 x$ $2x$ , then $y$ $y$ =(-4)x2= -8.

$x = - 4$ $x=-4$
$y = - 8$ $y=-8$

How do you solve y=x−4y=x-4 and y=2xy=2x using substitution?