Find the product of this expression.

(m + n2)(m2 - mn2 + n4) =

M^3 -m^2n^2 +mn^4 +m^2n^2 -mn^4 +n^6 =
= m^3 +n^6

(m + n^2) * (m^2 - m * n^2 + n^4)

m    * m^2           = m^3
m    * ( -m * n^2) = -m^2 * n^2 Cancels out
m    * n^4            = m * n^4      Cancels out

n^2 * m^2           = m^2 * n^2  Cancels out
n^2 * ( -m * n^2) = -m * n^4     Cancels out
n^2 * n^4            = n^6

Final
m^3 + n^6
Hope I helped :)