Answer:
x = -4; y = 8
Explanation:
Step 1: Multiply the first equation by -8:
-8(-2x - y = 0)
16x + 8y = 0
Step 2: Add 16x + 8y = 0 and -7x - 8y = 0 to eliminate y and solve for x:
16x + 8y = 0
+
-7x - 8y = -36
----------------------------------------------------------------------------------------------------------(16x - 7x) + (8y - 8y) = (0 - 36)
(9x = -36) / 9
x = -4
Thus, x = -4.
Step 3: Solve for y by plugging in -4 for x in -2x - y = 0:
-2(-4) - y = 0
(8 - y = 0 ) - 8
(-y = -8) / - 1
y = 8
Thus, y = 8.