Algebra

 2x - 5 <= -x + 12 - 7x + 18

Rearrange  as

10x <= 35

x <= 35  / 10

x <= 7 /  2

Put the terms with \(x\) on one side and the numbers on the other:

\(2x+x+7x \le 12+18+5\)

which simplifies to \(10x\le35\) 

So \(x= \dfrac{7}{2}\). 

I hope that helped!