Chapter 2 - Solving Equations - 2-1 Solving One-Step Equations - Practice and Problem-Solving Exercises - Page 85: 19

w=132

In order to solve this algebraic expression, we must isolate the variable. A variable is the letter in the problem (for instance, in the equation x+2=10, x is the variable). Because addition and subtraction are inverse operations (they cancel each other out), we know we must add when a number is being subtracted from the variable and subtract when a number is being added to the variable. In the equation 67=w-65, we must get rid of the 65, which is on the same side as w, in order to solve. Thus, we add 65 on both sides of the equation to find that w=132. We plug 132 in for w in our original equation and confirm that our answer is, indeed, correct.