Choose the best definition for the following phrase: like terms

1.A letter that holds the place for some unknown value in mathematics.

2.A process where you must look for terms that have identical variable parts and then combine their coefficients.

3.A process where if two things are equal, one can be put in the place of the other and nothing will change.

4.Terms that have identical variable parts.

Question

Choose the best definition for the following phrase: like terms 

 1.A letter that holds the place for some unknown value in mathematics. 

 2.A process where you must look for terms that have identical variable parts and then combine their coefficients. 

 3.A process where if two things are equal, one can be put in the place of the other and nothing will change. 

 4.Terms that have identical variable parts.

anonymous · Answer

2.  When you combine like terms you look for the same variable parts then combine the coefficients.  For example, 3x + 2x^2 - 2x + 1, 3x and -2x have the same exponent of 1.  They can be combined by doing 3x - 2x to get x.  So combine like terms for my example would be 2x^2 + x + 1.