Question

So sánh:

a) \(2^{30}+3^{30}+4^{30}\) và \(3.24^{10}\)

b) \(3^{21}\) và \(2^{31}\)

Answer 1

a) \(2^{30}+3^{30}+4^{30}=4^{15}+27^{10}+64^{10}>4^{15}+24^{10}+2.24^{10}>3.24^{10}\)

b) \(3^{21}=3.9^{10}>3.8^{10}>2.8^{10}=2^{31}\)

Answer 2

bạn trịnh tuấn việt làm đúng rồi đấy

Answer 3

a)Ta có: 
+) 3.24^10 = 3.2^30.3^10 = 2^30.3^11 < 2^30.3^12 = 2^30.9^6.
+) 2^30 + 3^30 + 4^30 = (2^30 + 4^30) + 3^30 > (2^30 + 4^30) 
= 2^30.(1 + 2^30) > 2^30.2^30 = 2^30.32^6

=> (2^30 + 3^30 + 4^30) > 3.24^10

b) 3^21 = (3^7)^3 = 2187^3 
2^31 < 2^33 = (2^11)^3 = 2048^3 
==> 3^21 > 2^33 > 2^31.

Answer 4

1+1=1+1=2-1=3-2

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Answer 5

Đinh Tuấn việt lm đúng r đó

Answer 6

\(a) 2^{30}+3^{30}+4^{30}=4^{15}+27^{10}+64^{10}>4^{15}+24^{10}+2.24^{10}>3.24^{10}\)

\(b)3^{21}=3.9^{10}>3.8^{10}>2.8^{10}>2.31\)

Answer 7

a,Ta có :

\(2^{30}+3^{30}+4^{30}\)\(=4^{15}+27^{10}+64^{10}\)

Mà \(4^{15}+27^{10}+64^{10}>4^{15}+24^{10}+2.24^{10}\)

\(\Rightarrow4^{15}+27^{10}+64^{10}>3.24^{10}\)

Hay \(2^{30}+3^{30}+4^{30}>3.24^{10}\)

b,Ta có : 

+,\(3^{21}=3.\left(3^2\right)^{10}=3.9^{10}\)

+,\(2^{31}=2.\left(2^3\right)^{10}=2.8^{10}\)

Mà \(3.9^{10}>3.8^{10}>2.8^{10}\)

\(\Rightarrow3.9^{10}>2.8^{10}\)

Hay \(3^{21}>2^{31}\)

Answer 8

Trả lời :..............................

Lớn hơn...............................

Hk tốt......................................

Answer 9

3²¹=3.9¹⁰>3.8¹⁰    (1)

2³¹=2.8¹⁰<3.8¹⁰           (2)

từ (1),(2) suy ra 3²¹>2²¹