Answer:
y=-6 z=-1
Step-by-step explanation:
5(3)+4y=-9
15+4y=-9
-15. -15
4y=-24
/4. /4
y=-6
-x+4y-2z=-25
-3+4(-6)-2z=-25
-3+-24-2z=-25
-27-2z=-25
+27. +27
-2z=2
/-2. /-2
z=-1