# Math Help - Like terms?

1. ## Like terms?

Quick question with the following addition
$
\frac{1(x-1)+1(x+2)}{(x+2)(x+3)(x-1)}=\frac{2x+1}{(x+2)(x+3)(x-1)}$

How are we able to combine the numerators in this case to produce 2x + 1? Usually when dealing with variables you are adding or subtracting like terms, but here I dont see it, if present.

Thanks

2. $1(x-1)+1(x+2)$
= $x-1+x+2$
Collect like terms
= $x+x-1+2$
= $2x+1$

3. Bah im blind tonight, thanks!