Answer:
9m+6m^2n
Step-by-step explanation:
12mn-3mn=9mn
4m^2n+2m^2n=6m^2n
==> 9m+6m^2n
or rewrite as 3m(3+2mn)
I believe the new cost of the item is $19.80
The last option.
Hope this helps!
Wait hold on
no