Respuesta :

DeAngeloStokes
0+1=1 
1-0=1
1x1=1
1/1=1
1 is in everything if this didnt help tell me
stephen4934
It's easy since all the variables have a after them they can be added and subtracted together.

15a-9a=6a
6a+20a=26a
26a-12a=14a
The simplest form is 14a