Hello from MrBillDoesMath!
Answer:
-30
Discussion:
-3b -3y -3a -3x => (rearrange terms so a,b and x,y together)
-3a - 3b - 3x - 3y => (factor 3 from each term)
-3(a+b) - 3(x+y) => (substitute values provided by problem)
-3(9) - 3(1) =>
-27 - 3 = -30
Regards,
MrB
