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

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

Remove parentheses.

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

Add $4 a^{3}$ and $7 a^{3}$ .

$11 a^{3} - 8 a - 4 a^{2} - 7 - 6 a$

Subtract $6 a$ from $- 8 a$ .

$11 a^{3} - 14 a - 4 a^{2} - 7$

Move $- 14 a$ .

$11 a^{3} - 4 a^{2} - 14 a - 7$