Simplify (3x^3-7-9x^2)+(10-3x^2-x+x^3)

$(3 x^{3} - 7 - 9 x^{2}) + (10 - 3 x^{2} - x + x^{3})$

Remove parentheses.

$3 x^{3} - 7 - 9 x^{2} + 10 - 3 x^{2} - x + x^{3}$

Add $3 x^{3}$ and $x^{3}$ .

$4 x^{3} - 7 - 9 x^{2} + 10 - 3 x^{2} - x$

Add $- 7$ and $10$ .

$4 x^{3} - 9 x^{2} + 3 - 3 x^{2} - x$

Subtract $3 x^{2}$ from $- 9 x^{2}$ .

$4 x^{3} - 12 x^{2} + 3 - x$

Move $3$ .

$4 x^{3} - 12 x^{2} - x + 3$