Write in Standard Form (2a^2b-5b^3+4a^4b^2)-(7b^3+8a^4b^2-7a^2b)

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

To write a polynomial in standard form, simplify and then arrange the terms in descending order.

$a x^{2} + b x + c$

Simplify each term.

Apply the distributive property.

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

Simplify.

Multiply $7$ by $- 1$ .

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

Multiply $8$ by $- 1$ .

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

Multiply $- 7$ by $- 1$ .

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

Remove parentheses.

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

Simplify by adding terms.

Add $2 a^{2} b$ and $7 a^{2} b$ .

$- 5 b^{3} + 4 a^{4} b^{2} - 7 b^{3} - 8 a^{4} b^{2} + 9 a^{2} b$

Subtract $7 b^{3}$ from $- 5 b^{3}$ .

$- 12 b^{3} + 4 a^{4} b^{2} - 8 a^{4} b^{2} + 9 a^{2} b$

Subtract $8 a^{4} b^{2}$ from $4 a^{4} b^{2}$ .

$- 12 b^{3} - 4 a^{4} b^{2} + 9 a^{2} b$

Reorder $- 12 b^{3}$ and $- 4 a^{4} b^{2}$ .

$- 4 a^{4} b^{2} - 12 b^{3} + 9 a^{2} b$