Solve the equation |2x − 5| £ 9

recall that |n| =

n if n>=0
-n if n<0

So, we have two possibilities.

If 2x-5 >= 0,
2x-5 = 9
x = 7

If 2x-5 < 0,
-(2x-5) = 9
2x-5 = -9
x = -2

So, x = -2,7