Provide your best answer for the following math problem. Give ONLY the answer, no other words or explanation.
For example:

Answer: <most likely answer, as short as possible; not a complete sentence, just the answer!>.

The problem is: if 9 a - b = 10 b + 60 = - 12 b - 2 a , what is the value of 11 a + 11 b ?
0
-50.