Answer:
4
Explanation:
To find the answer we will be using the order of operations to calculate the solution.

Add and subtract from left to right since there are no P, E, M, and D:
4 - 9 = -5
-5 + 5 = 0
0 - 1 = -1
-1 - 6 = -7
-7 + 11 = 4
= 4
Therefore the answer to this equation is "4".
I hope this helps.