Question

which is equivalent to the following expression (3m^2+2mn-n^2)+(m^2+4mn-n^2)

Answer 1

Answer:

4m² + 6mn - 2n²

Step-by-step explanation:

$(3m^2+2mn-n^2)+(m^2+4mn-n^2)\\\\=3m^2+2mn-n^2+m^2+4mn-n^2\qquad\text{combine like terms}\\\\=(3m^2+m^2)+(2mn+4mn)+(-n^2-n^2)\\\\=\boxed{4m^2+6mn-2n^2}$