Question

How do you combine `(5a + 9b) - (2a + 4b)`?

Answer 1

Regroup with the terms that include the variable `a` in one group and the terms that include the variable `b` in the other.

`(5a+9b)-(2a+4b)`

`=(5a-2a) + (9b-4b)`

(That's "5 aardvarks take away 2 aardvarks plus 9 baboons take away 4 baboons")

`=3a + 5b`