ta có : 5²⁰=(5⁴)⁵=625⁵

vì 625⁵>75⁵ nên 5²⁰>71⁵

\(\left(\frac{3}{8}\right)^5=\frac{243}{8^5}>\frac{125}{8^5}>\frac{125}{9^5}=\frac{125}{\left(3^2\right)^5}=\frac{125}{3^{10}}>\frac{125}{3^{15}}=\frac{5^3}{\left(3^5\right)^3}=\left(\frac{5}{243}\right)^3\)

=>\(\left(\frac{3}{8}\right)^5>\left(\frac{5}{243}\right)^3\)

co cach khac ko

#tranminhkhoi

K bn ak

\(\left(\frac{3}{8}\right)^5=\left(\frac{3}{2^3}\right)^5=\frac{3^5}{2^{15}}=\frac{243}{2^{15}}\) ; \(\left(\frac{5}{243}\right)^3=\left(\frac{5^3}{3^5}\right)^3=\frac{5^3}{3^{15}}=\frac{125}{3^{15}}\)

Chọn phân số \(\frac{243}{3^{15}}\) làm trung gian để so sánh.

Ta có : \(\frac{243}{2^{15}}>\frac{243}{3^{15}}\) ; \(\frac{243}{3^{15}}>\frac{125}{3^{15}}\)

Do đó \(\frac{243}{2^{15}}>\frac{125}{3^{15}}\)

    Vậy \(\left(\frac{3}{8}\right)^5>\left(\frac{5}{243}\right)^3\)

Tớ ko đc OLM lựa chọn, chắc tớ làm sai rồi !

(3/8)⁵= 3⁵/(2³)⁵=243/2¹⁵>243/3¹⁵>125/3¹⁵=5³/(3⁵)³=(5/3⁵)³=(5/243)³

suy ra (3/8)⁵>(5/243)³

\(243^5=\left(3^5\right)^5=3^{25}\)

\(3.27^8=3.\left(3^3\right)^8=3.3^{24}=3^{25}\)

Vậy\(243^5=3.27^8\)

\(243^5=\left(3^5\right)^5=3^{25}\)

\(3.27^8=3.\left(3^3\right)^8=3.3^{24}=3^{25}\)

Vậy suy ra : \(243^5=3.27^8\)

Như đặc cầu

Ta có: 243⁵=(3⁵)⁵=3^5.5=3²⁵

3.27⁸=3.(3³)⁸=3.3^3.8=3²⁵

=>3²⁵=3²⁵

Vậy 243⁵=3.27⁸

243⁵ = (3⁵)⁵ = 3²⁵

3 . 27⁸ = 3 . (3³)⁸ = 3²⁵

=> 243⁵ = 3 . 27⁸

ta có 243^5=(3^5)^5=3^25  (1)

        3.27^8=3.(3^3)^8=3.3^24=3^25  (2)

        Từ(1)và(2)=>243^5=3.27^8