Question

[ღ✣⊱❃ ๖ۣۜĦắc_ ๖ۣۜȾuyết_๖ۣۜ ʆ ệ ​​​​​...]

Bài 1 : So sánh :

a) 5³⁰ và 124¹⁸

b) 4²¹ và 64⁷

c) 874² và 870 x 878

Answer 1

[kudo shinichi]

a)\(5^{30}=\left(5^2\right)^{15}=25^{15}\)

Ta có: \(25^{15}< 124^{15}< 124^{18}\)

\(\Rightarrow5^{30}< 124^{18}\)

b) \(4^{21}=\left(4^3\right)^7=64^7\)

c) \(874^2=\left(870+4\right).874=870.874+4.874\)

\(870.878=870.\left(874+4\right)=870.874+870.4\)

Ta có: \(\left(870+4\right).874>870.874+4.870\)

\(\Rightarrow874^2>870.878\)

Tham khảo nhé~

Answer 2

[Park Jimin - Mai Thanh Hoa]

a) \(5^{30}\) và    \(124^{18}\)

\(5^{30}=\left(5^5\right)^6=3125^6\)

\(124^{18}=\left(124^3\right)^6=1906624^6\)

Vì \(3125< 1906624\)

Vậy \(5^{30}< 124^{18}\)

b) \(4^{21}\)  và      \(64^7\)

\(4^{21}=\left(4^3\right)^7=64^7\)

Vì \(64=64\)

Vậy \(4^{21}=64^7\)

c) \(874^2\) và      \(870.878\)

\(874^2=874.874=763876\)

\(870.878=763860\)

Vì \(763876>763860\)

Vậy \(874^2>870. 878\)