Answer:
x=-8,y=8
Step-by-step explanation:
make y the subject
y=-2x-8 eqn 3
the substitute into equation 1
3(-2x-8)=24
open bracket
-6x-24=24
carry -24 to the other side
-6x=24+24
-6x=48
divide through by -6
x=-8
then sub x=-8 into equation 3
y=-2(-8)-8
y=16-8
=8