Pleaase need ! add the polynomial expression find each sum vertically (y^2 - x^4) + (x^4 - x^2)

Y^2  -  x^4 
        + x^4  - x^2

y^2 -    0    - x^2

y^2 - x^2

This is what i found “an explicit formula designates the nth term of the sequence, as an expression of n (where n = the term's location). it defines the sequence as a formula in terms of n. this example is an arithmetic sequence(the same number, 5, is added to each term to get to the next term).” i hope this you for what your looking for. can you plz mark me brainliest?