Simplify (2x^2-4y+7xy-6y^2)-(-3x^2+5y-4xy+y^2)

$(2 x^{2} - 4 y + 7 x y - 6 y^{2}) - (- 3 x^{2} + 5 y - 4 x y + y^{2})$

Simplify each term.

Apply the distributive property.

$2 x^{2} - 4 y + 7 x y - 6 y^{2} - (- 3 x^{2}) - (5 y) - (- 4 x y) - y^{2}$

Simplify.

Multiply $- 3$ by $- 1$ .

$2 x^{2} - 4 y + 7 x y - 6 y^{2} + 3 x^{2} - (5 y) - (- 4 x y) - y^{2}$

Multiply $5$ by $- 1$ .

$2 x^{2} - 4 y + 7 x y - 6 y^{2} + 3 x^{2} - 5 y - (- 4 x y) - y^{2}$

Multiply $- 4$ by $- 1$ .

$2 x^{2} - 4 y + 7 x y - 6 y^{2} + 3 x^{2} - 5 y + 4 (x y) - y^{2}$

$2 x^{2} - 4 y + 7 x y - 6 y^{2} + 3 x^{2} - 5 y + 4 x y - y^{2}$

Simplify by adding terms.

Add $2 x^{2}$ and $3 x^{2}$ .

$5 x^{2} - 4 y + 7 x y - 6 y^{2} - 5 y + 4 x y - y^{2}$

Subtract $5 y$ from $- 4 y$ .

$5 x^{2} + 7 x y - 6 y^{2} - 9 y + 4 x y - y^{2}$

Add $7 x y$ and $4 x y$ .

$5 x^{2} + 11 x y - 6 y^{2} - 9 y - y^{2}$

Subtract $y^{2}$ from $- 6 y^{2}$ .

$5 x^{2} + 11 x y - 7 y^{2} - 9 y$