2) (4m-4(m-n))/(m-n)(m+n)=
=(4m-4m+4n)/(m²-n²)
4) (x²+y²-(x-y)(x-y))/(x²-y²)=
=(x²+y²-x²+y²)/(x²-y²)=
=2y²/(x²+y²)
6) (2+m+2m)/(-(2(2-m)(2+m)
=(2+3m)/(-2(4-m²)=
=(2+3m)/(2m²-8)
B
2) (m(2m-20)+4m(m+2)- -6(m²-4)/(m(m²-4)=
=(2m²-20m+4m²+8m-6m²+
+24)/(m(m²-4)=
=(24-12m)/(m(m-2)(m+2)=
=(-12(m-2)/(m(m-2)(m+2)=
=(-12)/(m(m+2)