Cho abc=2020. Rút gọn A= $\frac{2020a}{ab+2020a+2020}$ + $\frac{b}{bc+b+2020}$ + $\frac{c}{ac+c+1}$

0 bình luận về “Cho abc=2020. Rút gọn A= $\frac{2020a}{ab+2020a+2020}$ + $\frac{b}{bc+b+2020}$ + $\frac{c}{ac+c+1}$”

1. Giải thích các bước giải:

   Ta có :

   $A=\dfrac{2020a}{ab+2020a+2020}+\dfrac{b}{bc+b+2020}+\dfrac{c}{ac+c+1}$

   $\to A=\dfrac{2020a}{ab+2020a+2020}+\dfrac{ab}{abc+ab+2020a}+\dfrac{abc}{ab.ac+abc+ab}$

   $\to A=\dfrac{2020a}{ab+2020a+2020}+\dfrac{ab}{2020+ab+2020a}+\dfrac{2020}{2020a+2020+ab},abc=2020$

   $\to A=\dfrac{2020a+ab+2020}{2020a+2020+ab}$

   $\to A=1$

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