You can put this solution on YOUR website! Apply the distributive property and combine like terms:
x - [3x - 18 + 2x - x] < x - 5 + x
x - [4x - 18] < 2x - 5
x - 4x + 18 < 2x - 5
-3x + 18 < 2x - 5
Isolate the variables and constants:
-3x - 2x < -5 - 18
-5x < -23 <
x > [don't forget to switch the < to > since you're dividing by a negative number]
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