Simplify -10a^2+6a^3+3a-6a^3-4a+8a^2

$- 10 a^{2} + 6 a^{3} + 3 a - 6 a^{3} - 4 a + 8 a^{2}$

Combine the opposite terms in $- 10 a^{2} + 6 a^{3} + 3 a - 6 a^{3} - 4 a + 8 a^{2}$ .

Subtract $6 a^{3}$ from $6 a^{3}$ .

$- 10 a^{2} + 3 a + 0 - 4 a + 8 a^{2}$

Add $- 10 a^{2} + 3 a$ and $0$ .

$- 10 a^{2} + 3 a - 4 a + 8 a^{2}$

Add $- 10 a^{2}$ and $8 a^{2}$ .

$- 2 a^{2} + 3 a - 4 a$

Subtract $4 a$ from $3 a$ .

$- 2 a^{2} - a$