Tìm gtln của:

A=\(\frac{1}{a^3+b^3+1}+\frac{1}{b^3+c^3+1}+\frac{1}{c^3+a^3+1}\)với a,b,c là các số dương và abc=1

1. this was only a small company with saveral years of low profit but now it has changed a lot

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2. men were the breadwinner of the family and women depended greatly on men

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3.my sister admitted that she lied sometimes in the past but now she didn't

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4. Jim asked me that i preferred to do as a child that i no longer did now

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5. who took care of you when you were a toddler?

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6. Jim wasn't interested in reading books when he was small but now he is really into it

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7. i got all the attention from my parents before my little brother was born

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8. bungalows were very popular 6 years ago

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Cho bt:R=\(\left(\frac{\left(x-1\right)^2}{3x+\left(x-1\right)^2}-\frac{1-2x^2+4x}{x^3-1}+\frac{1}{x-1}\right):\frac{x^2+x}{x^3+x}\)

a/Tìm điều kiện để R xác định

b/Tìm gtri của x để R =0

c/Tìm gtri của x để/R/ =1

\(x^2-4xy+4y^2-9a^2\)