Question

what is the answer for 1+1+7x​2​​+7y​3​​+3+2x​2​​−y​3​​

Answer 1

First, a little housekeeping!!

1+1+7x​2​​+7y​3​​+3+2x​2​​−y​3​​ needs to be written as 1+1+7x​^2​​+7y​^3​​+3+2x​^2​​−y​^3.  The " ^ " signifies exponentiation and is essential here.

Now combine like terms:

7y^3-y^3   +   7x^2 + 2x^2 + 1 + 1 + 3

You'll get     6y^3 +9x^2 +  5.​​