1) =a-0.2b / 5(a²+0.2ab+0.04b²) + 0.6ab/ 5(a³-0.008b³) + 0.2/ a-0.2b=
общий знаменатель 5(a-0,2b)(a²+0.2ab+0.04b²)
=a²-0.4ab+0.04b²+0.6ab+a²+0.2ab+0.04b² / 5(a-0.2b)(a²+0.2ab+0.04b²)=
=2a² +0.4ab+0.08b² / 5(a-0.2b)(a²+0.2ab+0.04b²)=
=2(a²+0.2ab+0.04b²) / 5(a-0.2b)(a²+0.2ab+0.04b²)=2/ 5 (a-0.2b)
2)2/ 5(a-0.2b) * 5a-b/ 2=2/ 5a-b * 5a-b /2 =1