Simplify 3-(2m^2+3)+(m^2-2m+3)

$3 - (2 m^{2} + 3) + (m^{2} - 2 m + 3)$

Remove parentheses.

$3 - (2 m^{2} + 3) + m^{2} - 2 m + 3$

Simplify each term.

Apply the distributive property.

$3 - (2 m^{2}) - 1 \cdot 3 + m^{2} - 2 m + 3$

Multiply $2$ by $- 1$ .

$3 - 2 m^{2} - 1 \cdot 3 + m^{2} - 2 m + 3$

Multiply $- 1$ by $3$ .

$3 - 2 m^{2} - 3 + m^{2} - 2 m + 3$

Simplify by adding terms.

Combine the opposite terms in $3 - 2 m^{2} - 3 + m^{2} - 2 m + 3$ .

Subtract $3$ from $3$ .

$- 2 m^{2} + 0 + m^{2} - 2 m + 3$

Add $- 2 m^{2}$ and $0$ .

$- 2 m^{2} + m^{2} - 2 m + 3$

Add $- 2 m^{2}$ and $m^{2}$ .

$- m^{2} - 2 m + 3$