Your original inequality is
.. w -2 ≤ 8
The additive property of equality applies to inequalities as well as to equations. You use the additive property of equality to solve this. Add 2 to both sides.
.. w -2 +2 ≤ 8 +2
The purpose of adding 2 is to cancel the effect of subtracting 2. That is, -2+2=0, and w+0 = w.
.. w ≤ 10
The correct selection would be B.