2
1)4(a+b)²/ab-16=(4a²+8ab+4b²-16ab)/ab=4(a-b)²/ab
2)[(a+b)²-ab]/ab=(a²+2ab+b²-ab)/ab=(a²+ab+b²)/ab
3)4(a-b)²/ab*(a²+ab+b²)/ab*10ab/[(a-b)(a²+ab+b²)]=40(a-b)/ab
3
1)a/(a+b)+b/(a-b)-2ab/(a-b)(a+b)=((a²-ab+ab+b²-2ab)/(a²-b²)=
=(a-b)²/(a-b)(a+b)=(a-b)/(a+b)
2)a/(a+b)+b/(a-b)+2ab/(a-b)(a+b)=(a²-ab+ab+b²+2ab)/(a²-b²)=
=(a+b)²/(a-b)(a+b)=(a+b)/(a-b)
3)(a-b)/(a+b)*(a+b)/(a-b)=1
4
1)2/(2+m)+m/(2-m)-4m/(2+m)(2-m)=(4-2m+2m+m²-4m)/(4-m²)=
=(2-m)²/(2-m)(2+m)=(2-m)/(2+m)
2)2/(2+m)+m/(2-m)-4m/(2-m)(2+m)=(4-2m+2m+m²-4m)/(4-m²)=
=(2-m)²/(2-m)(2+m)=(2-m)/(2+m)
3)(2-m)/(2+m):(2-m)/(2+m)=1