Simplify (6n^2+3n^4-8n-4n^3)+(7n^2-8n^3-2n)

$(6 n^{2} + 3 n^{4} - 8 n - 4 n^{3}) + (7 n^{2} - 8 n^{3} - 2 n)$

Remove parentheses.

$6 n^{2} + 3 n^{4} - 8 n - 4 n^{3} + 7 n^{2} - 8 n^{3} - 2 n$

Add $6 n^{2}$ and $7 n^{2}$ .

$3 n^{4} - 8 n - 4 n^{3} + 13 n^{2} - 8 n^{3} - 2 n$

Subtract $2 n$ from $- 8 n$ .

$3 n^{4} - 4 n^{3} + 13 n^{2} - 8 n^{3} - 10 n$

Subtract $8 n^{3}$ from $- 4 n^{3}$ .

$3 n^{4} - 12 n^{3} + 13 n^{2} - 10 n$