Let a number and the number be an arbitrary variable. Let's call it x. We have an algebraic expression. Let's take it in pieces:
- 7 times a number: 7x
- 4 times the number: 4x
- The phrase increased by means we add 4x to 7x:
- 7x + 4x
- Simplifying, we get: (7 + 4)x
- 11x
