Ta có: \(\left(0,343\right)^7=\left[\left(0,7\right)^3\right]^7=\left(0,7\right)^{21}\)
Vì \(\left(0,7\right)^{21}< \left(0,7\right)^{20}\) nên \(\left(0,343\right)^7< \left(0,7\right)^{20}\)
\(\Rightarrow\) Chọn đáp án \(\left(0,343\right)^7< \left(0,7\right)^{20}\)
#Urushi