0=5+(-11)-(-11)
We simplify the equation to the form, which is simple to understand
0=5+(-11)-(-11)
Remove unnecessary parentheses
0=+5-11-(-11+)
Remove unnecessary parentheses
0=5-11+11
We move all terms containing to the left and all other terms to the right.
0=+5-11+11-0
We simplify left and right side of the equation.
0=+5
0=5
The left and right sides are not equal, therefore there is no solution. This equation is invalid.