Simplify (-4a^2-3b)+(-2ab-a^2+b^2)+(-b^2+6ab)

$(- 4 a^{2} - 3 b) + (- 2 a b - a^{2} + b^{2}) + (- b^{2} + 6 a b)$

Remove parentheses.

$- 4 a^{2} - 3 b - 2 a b - a^{2} + b^{2} - b^{2} + 6 a b$

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

Subtract $b^{2}$ from $b^{2}$ .

$- 4 a^{2} - 3 b - 2 a b - a^{2} + 0 + 6 a b$

Add $- 4 a^{2} - 3 b - 2 a b - a^{2}$ and $0$ .

$- 4 a^{2} - 3 b - 2 a b - a^{2} + 6 a b$

Subtract $a^{2}$ from $- 4 a^{2}$ .

$- 5 a^{2} - 3 b - 2 a b + 6 a b$

Add $- 2 a b$ and $6 a b$ .

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