Задание в пичке-2)))))))

Question

Задание в пичке-2)))))))

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Answer 1

1)1/(x-1)-(x²-x+1)/[(x-1)(x²+x=1)]-1/(x²+x+1)=
=(x²+x+1-x²+x-1-x+1)/(x³-1)=(x+1)/(x³-1)
2)1/(1-x)+x/[(1-x)(1+x)]-x/(x+1)=(x+1+x-x+x²)/(1-x²)=(x²+x+1)/(1-x²)
3)(x+1)/(x³-1)(*(x²+x+1)/(1-x²)=(x+1)/[(x-1)(x²+x+1)] * (x²+x+1)/[(1-x)(1+x)]=
=1/[(x-1)(1-x)]=-1/(x-1)²