Answer:
-34
Step-by-step explanation:
a + b = -6
x + y + z = -2
We want 8a so multiply the first equation by 8
8( a + b) = -6*8
8a+8b = -48
We also want -7x so multiply the second equation by -7
-7(x + y + z) = -2*-7
-7x-7y-7z = 14
Add the two equations together
8a+8b = -48
-7x-7y-7z = 14
-------------------------
8a+8b-7x-7y-7z = -34
Rearranging the order
8a - 7x - 7z - 7y + 8b = -34
