Question 623489
(r-4s+6)+(8r+3s)+(s+9)


r-4s+6+8r+3s+s+9


(r+8r)+(-4s+3s+s)+(6+9)


9r+0s+15


9r+15


So (r-4s+6)+(8r+3s)+(s+9) simplifies to <font color="red">9r+15</font>