1
1)2/(2a-b)-6b/(2a-b)(2a+b)-4/(2a+b)=(4a+2b-6b-8a+4b)/(4a²-b²)=-4a/(4a²-b²)
2)1 +(4a²+b²)/(4a²-b²)=(4a²-b²+4a²+b²)/(4a²-b²)=8a²/(4a²-b²)
3)-4a/(4a²-b²):8a²/(4a²-b²)=-4a/(4a²-b²) * (4a²-b²)/8a²=-1/2a
2
1)3a/(a-b)(a²+ab+b²) * (a²+ab+b²)/(a+b)=3a/(a-b)(a+b)
2)3a/(a-b)(a+b) + 3/(a-b)=(3a+3a+3b)/(a-b)(a+b)=(6a+3b)/(a-b)(a+b)=
=3(2a+b)/(a-b)(a+b)
3)3(2a+b)/(a-b)(a+b) : (2a+b)/(a+b)²=3(2a+b)/(a-b)(a+b) * (a+b)²/(2a+b)=3(a+b)/(a-b)
4)3(a+b)/(a-b)*3/(a+b)=9/(a-b)