if you add 7 to 2x, the result is 17 Add 7 to 2x: 2x + 7 The phrase the result is means an equation, so we set 2x + 7 = 17 2x + 7 = 17 <-- This is our algebraic expression Now, if you want to solve for x, type in 2x + 7 = 17 into the search engine, and we get x = 5.