Question

so sánh

15^15và 81^3x125^5

Answer 1

Ta có : \(15^{15}=3^{15}.5^{15}\)

\(81^3.125^5=3^{12}.5^{15}\)

Ta thấy : \(5^{15}=5^{15}\)

mà : \(3^{15}>3^{12}\)

\(=>15^{15}>81^3.125^5\)

Answer 2

Ta có:

15¹⁵ = 3¹⁵.5¹⁵

81³.125⁵ = (3⁴)³.(5³)⁵ = 3¹².5¹⁵ 

Vì 3¹⁵.5¹⁵ > 3¹².5¹⁵

=> 15¹⁵ > 81³.125⁵

Answer 3

Ta có:

\(15^{15}=\left(3\times5\right)^{15}=3^{15}\times5^{15}\)

\(81^3\times125^5=\left(3^4\right)^3\times\left(5^3\right)^5=3^{12}\times5^{15}\)

Vì \(3^{15}\times5^{15}>3^{12}\times5^{15}\);

nên\(15^{15}>81^3\times125^5\)