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Тождество доказано

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Ответ:

Объяснение:

1. 2a/(a+3)-4a/(a²+6a+9)=2a/(a+3)-4a/(a+3)²=(2a*(a+3)-4a)/(a+3)²=

=(2a²+6a-4a)/(a+3)²=(2a²+2a)/(x+3)²=2a*(a+1)/(a+3)².

2. (2a*(a+1)/(a+3)²):((a+1)/(a²-9))=2a*(a+1)*(a+3)*(a-3)/((a+3)²*(a+1))=

=2a*(a-3)/(a+3)=(2a²-6a)/(a+3).

3. ((2a²-6a)/(a+3))-((a²-9a)/(a+3))=(2a²-6a-a²+9a)/(a+3)=(a²+3a)/(a+3)=

=a*(a+3)/(a+3)=a.