I need help with #14 & #15 quickly! [Simplifying monomials]

I will give brainliest if it is correct.
Random answers will be reported!

#14   #15

Step-by-step explanation with pictures.

I hope this helps! :D

Sales tax  is the  tax  on the  sale  or lease of goods, and is what is known as a “pass-through  tax.” unlike  income tax,  sales taxes  is decided and administered by state governments only. merchants are required to collect  sales tax  from their customers and remit it back to the state, essentially acting as  tax  collectors.