Respuesta :

so we have
y=-2x-6
y=x+9
elimination
multiply second by e
2y=2x+18
just add them

y=-2x-6
2y=2x+18  +
3y=0x+12
3y=12
divide by 3
y=4
subsitue
4=x+9
subtract 9
-5=x

x=-5
y=4