Collecting like terms means to simplify terms in expressions in which the variables are the same. In the expression \(5a + 2b + 3a - 6b\), the terms \(5a\) and \(+ 3a\) are like terms, as are \(2b ...

It may be possible to simplify an expression by collecting like terms together ... 4y\) and \(9y^2\) are not like terms but \(4y^2\) and \(9y^2\) are.