Balance an Equation

2(2x - 3) + 2 + [?] = 7x - 4.
What term makes this equation true for all values of x?

2(2x - 3) + 2 + [?] = 7x - 4
4x - 6 + 2 + ? = 7x - 4 {distributive property}
4x - 4 + ? = 7x - 4 {combined like terms}

looks like ? = 3x, that will make both sides equal

4x - 4 + 3x = 7x - 4 {put 3x in for ?}
7x - 4 = 7x - 4 {combined like terms}

- Algebra House