+314 Because the absolute value of a number is really just the units it is away from the origin, or 0. Now lets simplify the equation.
lxl+3=5
lxl+3-3=5-3
lxl=-2 or +2.
-2 and 2 are the only two numbers that are 2 units away from 0, and so either of them could be the answer.
