Solve each system by substitution

x+3y=-4

y+x=0

To figure this out, you would first isolate one of the variables in one of the two equations given.

I will first isloate the second equation's Y by subratcting it on both sides to get it onto the other side, thus not changing any of the values in the equation, just moving it around.

The equation would be: x=0+y or simply x=y

You plug in the x to the first equation with parenthesis around it to get it all into on equation: (y) + 3y=-4

Add the two like terms, y and 3y to get 4y=-4

Divide that equation by four on both sides to get y=-1

Plug - 1 into the second equation that you had moved around (x=y) to get x=-1

So - 1=y and - 1=x