1.(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b) 2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2

1.(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b) 2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2
1.(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b) 2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2

1.(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b) 2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2
(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b) =(a^2-b^2)^2/(a+b)^2/(a-b) =(a-b)^2(a+b)^2/(a+b)^2/(a-b) =a-b

1.(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b)
=(a^2-b^2)²/(a+b)^2/(a-b)
=(a+b)²(a-b)² * (a-b)/(a+b)²
=(a-b)³
2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2
=(m-2n)(m+2n-m+2n)/(-3n)^2
=(m-2n) *4n/ 9n²
=4/9 * (m-2n)/ n

(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b) 2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2
=(a^2-b^2)^2/(a+b)^2/(a-b)
=(a+b)^2/(a-b)^2/[(a+b)^2(a-b)]
=a-b
[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2
=[(m-2n)(m+2n-m+2n)/(3n)^2
=(m-2n)*4n/(3n)^2
=4/9(m-2n)/n

1.(a^4-2a^2b^2+b^4)/(a+b)^2/(a-b)
=(a^2-b^2)^2/ (a+b)^2/(a-b)
=(a-b)^2/(a-b)
=a-b
2.[(m+2n)(m-2n)-(m-2n)^2]/(-3n)^2
=[(m-2n)(m+2n-m+2n)]/(-3n)^2
=(m-2n)*4/9n
=4(m-2n)/(9N)