Like and Unlike Terms

When terms have the same algebraic factors, they are likeunlike terms.

When terms have different algebraic factors, they are unlikelike terms.

For example:

In the expression 2xy – 3x + 5xy – 4, look at the terms 2xy and 5xy. The factors of 2xy are , x and y. The factors of 5xy are ,x and y. Thus their algebraic (i.e., those which contain variables) factors are the same and hence they are like terms.

On the other hand the terms 2xy and –3x, have different algebraic factors. They are unlikelike terms. Similarly, the terms 2xy and 4, are unlike terms. Also, the terms –3x and 4 are unlike terms.