Simplify (3m^2+2mn-n^2)+(m^2+4mn-n^2)

$(3 m^{2} + 2 m n - n^{2}) + (m^{2} + 4 m n - n^{2})$

Step 1

Remove parentheses.

$3 m^{2} + 2 m n - n^{2} + m^{2} + 4 m n - n^{2}$

Step 2

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

$4 m^{2} + 2 m n - n^{2} + 4 m n - n^{2}$

Step 3

Add $2 m n$ and $4 m n$ .

$4 m^{2} - n^{2} + 6 m n - n^{2}$

Step 4

Subtract $n^{2}$ from $- n^{2}$ .

$4 m^{2} - 2 n^{2} + 6 m n$