How do you solve the system of equations $3x = - 3( 2y - 4)$ and $9x + 18y = 36$ by using the addition method?

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Answer 1 · 2017-08-14T08:31:25

$x=2$
$y=1$
BUT..

To my mind, you can not solve this system by using the addition method.
1) $3x=-6y+12$ and
$36=9x+18y$

2) $3x+6y=12$ |× (-3)
$9x+18y=36$

3) $-9x-18y=-36$
$9x+18y=36$

4) so, when you do the next step, you get that $0=0$ and then you can not continue the solving.

How do you solve the system of equations 3x = - 3( 2y - 4)3x = - 3( 2y - 4) and 9x + 18y = 369x + 18y = 36 by using the addition method?