1)(2a-2b)/(a²-b²)=(2(a-b))/((a+b)(a-b))=2/(a+b)
2)(5a+5b)²/(a²+2ab+b²)=5²(а²+2ab+b²)/(a²+2ab+b²)=25
3)a²-100/a²-20a+100=((a-10)(a+10))/(a-10)²=((a-10)(a+10))/((a-10)(a-10))=(a+10)/(a-10)
1)=2 (3/4корень из6+2)-0,75<span>√6=2</span>
<span>2)=6,3</span>