How do you solve #abs(5-x)<=x#?
Use the piecewise definition of the absolute value function,
Solve both inequalities.
Separate into two inequalities:
Distribute the minus sign in the second inequality:
Add x to both sides of the first inequality and subtract x from both sides of the second:
The second inequality does not depend on x, therefore, we discard it.
Divide both sides of the first inequality by 2:
Flip the inequality