Question

\\(9n^6 + 4n^4 - 5) + (3n^6 + 2n^4 + 8)\\

Explanation:

Group like terms

$$ (9n^6 + 3n^6) + (4n^4 + 2n^4) + (-5 + 8) $$

Combine coefficients

$$ (9 + 3)n^6 + (4 + 2)n^4 + 3 $$

Simplify expression

$$ 12n^6 + 6n^4 + 3 $$

Answer:

$$12n^6 + 6n^4 + 3$$