Take the constants to the right side of the equation
|5-x|=13/4-3/4
|5-x|=5/2
When you remove the absolute value on the left side, you have to put a plus or minus sign, +- on the right side.
5-x=+-5/2
Solve for the positive equation:
5-x=5/2
-x=-5/2
x=5/2
Solve for the negative equation:
5-x=-5/2
-x=-15/2
x=15/2
Solution: x= 5/2, 15/2