Question

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

Answer 1

`x=2`
`y=1`
BUT..

Explanation:

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.