Срочно, пожалуйста, даю 10 баллов, спасибо заранее)
1. 1) (6a/(2a+5)-16a/(4a²+20a+25)=6a/(2a+5)-16a/((2a)²+2*2a*5+5²)= =6a/(2a+5)-16a/(2a+5)²=(6a*(2a+5)-16a)/(2a+5)²=(12a²+30a-16a)/(2a+5)²= =(12a²+14a)/(2a+5)²=2a*(6a+7)/(2a+5)². 2) 2a*(6a+7)/(2a+5)²:(6a+7)/(4a²-25)=2a*(6a+7)*(2a+5)*(2a-5)/((6a+7)*(2a+5)²)= =2a*(2a-5)/(2a+5). 3) 2a*(2a-5)/(2a+5)+(10a-25)/(2a+5)=(2a*(2a-5)+5*(2a-5))/(2a+5)= =(2a-5)*(2a+5)/(2a+5)≡2a-5. 2. 1) 5x/(x-10)+20x/(x²-20x+100)=5x/(x-10)+20x/(x-10)²=(5x*(x-10)+20x)/(x-10)²= =(5x²-50x+20x)/(x-10)²=(5x²-30x)/(x-10)²=5x*(x-6)/(x-10)². 2) 5x*(x-6)/(x-10)²:(4x-24)/(x²-100)=5x*(x-6)*(x-10)*(x+10)/((x-10)²*4*(x-6))= =(5x*(x+10))/(4*(x-10)). 3) (5x*(x+10))/(4*(x-10))-25x/(x-10)=(5x²+50x-100x)/(4*(x-10))= =(5x²-50x)/(4*(x-10))=5x*(x-10)/(4*(x-10))≡5x/4.