Answer:
z = 1/2 or 0.5
Step-by-step explanation:
13 - 3z = 15z + 4
+3z +3z
13 = 18z + 4
-4 -4
9 = 18z
z = 9/18
x= 83y−17 and y= 83x+17
hope it helps
13 + (-20) = 13 - 20 = -7
HOPE IT HELPS