Simplify (-9n^4+8)-(-9n^4+2n^3+5n^2)

$(- 9 n^{4} + 8) - (- 9 n^{4} + 2 n^{3} + 5 n^{2})$

Simplify each term.

Apply the distributive property.

$- 9 n^{4} + 8 - (- 9 n^{4}) - (2 n^{3}) - (5 n^{2})$

Simplify.

Multiply $- 9$ by $- 1$ .

$- 9 n^{4} + 8 + 9 n^{4} - (2 n^{3}) - (5 n^{2})$

Multiply $2$ by $- 1$ .

$- 9 n^{4} + 8 + 9 n^{4} - 2 n^{3} - (5 n^{2})$

Multiply $5$ by $- 1$ .

$- 9 n^{4} + 8 + 9 n^{4} - 2 n^{3} - 5 n^{2}$

Simplify by adding terms.

Combine the opposite terms in $- 9 n^{4} + 8 + 9 n^{4} - 2 n^{3} - 5 n^{2}$ .

Add $- 9 n^{4}$ and $9 n^{4}$ .

$0 + 8 - 2 n^{3} - 5 n^{2}$

Add $0$ and $8$ .

$8 - 2 n^{3} - 5 n^{2}$

Move $8$ .

$- 2 n^{3} - 5 n^{2} + 8$