okay so it really easy. EX: 6x + 4x^2 - 2x + 3x^2 - 7x^5
So basically 6x - 2x because both of them have x and are raised to the power of 1. While 4x^2 + 3x^2 go together because they are both raised to the 2nd power. While -7x^5 doesn't go with any terms because no terms are raised to the 5th power.
For someone to be able to answer this question you need to include the weights. Im trying to help but we cant help unless you give the amount of weight. :(