Question

so sánh:

1990¹⁰ + 1990⁹ và 1991¹⁰

Answer 1

Ta có :

\(1990^{10}+1990^9=199^9\left(199.10^9\right)\)

\(1991^{10}>1990^{10}=199^{10}.10^{10}=199^9.199.10^{10}\)

Vì \(199^9\left(199.10^9\right)< 199^9.199.10^{10}=1991^{10}\)

\(\Rightarrow199^{10}+1990^9< 1991^{10}\)

Answer 2

1990¹⁰ + 1990⁹ = 9,744261891 x 10³²

1991¹⁰ = 9,788420103 x 10³²

Vì 9,744261891 x 10³² < 9,788420103 x 10³²

Nên 1990¹⁰ + 1990⁹ < 1991¹⁰