$\sqrt[]{2019^{2}+ 2019.2020+2020^{2}}$
=$\sqrt[]{\frac{(2020-2019)(2019^{2}+ 2019.2020+2020^{2})}{2020-2019} }$
=$\sqrt[]{\frac{(2020-2019)(2019^{2}+ 2019.2020+2020^{2})}{1} }$
=$\sqrt[]{{(2020-2019)(2019^{2}+ 2019.2020+2020^{2})} }$
=$\sqrt[]{2020^{3}-2019^{3}}$
=$\sqrt[]{67836442614404472000}$
@thuyylinhh20042007
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