Ta có :
\(\left(\frac{16}{25}\right)^{10}=\left(\frac{4^2}{5^2}\right)^{10}=\left(\frac{4}{5}\right)^{2.10}=\left(\frac{4}{5}\right)^{20}\)
\(\left(\frac{3}{7}\right)^{40}=\left(\frac{3}{7}\right)^{2.20}=\left(\frac{3^2}{7^2}\right)^{20}=\left(\frac{9}{49}\right)^{20}\)
Vì 20 = 20 và \(\frac{4}{5}>\frac{9}{49}\)nên \(\left(\frac{4}{5}\right)^{20}>\left(\frac{9}{49}\right)^{20}\)
Vậy \(\left(\frac{16}{25}\right)^{10}>\left(\frac{3}{7}\right)^{40}\)
Đúng 0
Bình luận (0)
