1. 2a + 3a = 5a
2. 4x - 2x = 2x
3. x * x = x sq or x^2
4. 7x / x (x and x cancels out from the numerator and denominator, so we are left with 7 / 1 or 7) = 7
5. 5x + 3x - 4x = 4x
b. 4a^2 + a^2 + 2a^2 = 7a^2
b. 15x^2 - 5x^2 = 10x^2
b. a^2 * a * a^2 = a^5
b. 4ab / 2ab = 2
b. 4x^2 - x^2 - x^2 = 2x^2
Hope you understood the above. If you need any help I will be make sure to help you.