|2x+1| greater than or equal to |x-3|

Answer 1

you have to solve 4 problems:

(2x+1) >= (x-3)
(2x+1) >= -(x-3)
-(2x+1) >= (x-3)
-(2x+1) >= -(x-3)

some may have no solution, since it may not satisfy the initial condition.