If a + b + c = 8 and x + y = - 7, what is - 6a-6c-6y-6x-6b?

Add the two given equations a+b+c = 8 and x+y = - 7 to get

(a+b+c) + (x+y) = 8 + (-7)

a+b+c+x+y = 1

now multiply both sides by - 6 and rearrange terms

a+b+c+x+y = 1

-6 * (a+b+c+x+y) = - 6*1

-6a-6b-6c-6x-6y = - 6

-6a-6c-6y-6x-6b = - 6

Answer: - 6