Simplify (7x^3+7x^2-4)+(x^3-5x^2-3x+8)

$(7 x^{3} + 7 x^{2} - 4) + (x^{3} - 5 x^{2} - 3 x + 8)$

Remove parentheses.

$7 x^{3} + 7 x^{2} - 4 + x^{3} - 5 x^{2} - 3 x + 8$

Add $7 x^{3}$ and $x^{3}$ .

$8 x^{3} + 7 x^{2} - 4 - 5 x^{2} - 3 x + 8$

Subtract $5 x^{2}$ from $7 x^{2}$ .

$8 x^{3} + 2 x^{2} - 4 - 3 x + 8$

Add $- 4$ and $8$ .

$8 x^{3} + 2 x^{2} - 3 x + 4$