Respuesta :

akephd
X+y=12
And -x=-y-10 which if multiply through by -1 is same as x=y+10
So substitute this in first equation.
Y+10+y=12
2y=2
y=1

So x+1=12 so x=11

Check in other equation: -11=-1-10 so -11=-11 it works

So...x=11, y=1