(m2+3n)(m2-n) (a+2n2)(a2+n) (x2-a)(x2+a) (3+c3)(5-c2) ,

(m2+3n)(m2-n) = m^4 - m^2n +3m^2n -3n^2 = m^4 +2m^2n -3n^2

(a+2n2)(a2+n) = a^3 +an +2a^2n^2 +2n^3

(x2-a)(x2+a) = x^4 - a^2

(3+c3)(5-c2) = 15 -3c^2 +5c^3 -c^6