A = $2019^{2020}$ – $2019^{2019}$ + $2019^{2018}$ – $2019^{2017}$ + … + $2019^{2}$ + 2019

0 bình luận về “A = $2019^{2020}$ – $2019^{2019}$ + $2019^{2018}$ – $2019^{2017}$ + … + $2019^{2}$ + 2019”

1. $A=2019^{2020}-2019^{2019}+…+2019^2-2019$

   $⇒2019A=2019^{2021}-2019^{2020}+…+2019^3-201^2$

   $⇒2019A+A=2019^{2021}+(2019^{2020}-2019^{2020}+…-2019$

   $⇒2020A=2019^{2021}-2019$

   $⇒A=$$\frac{2019^{2021}-2019}{2020}$ 

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