a) \(63^7\)và \(16^{12}\)
Có \(63^7< 64^7=\left(2^6\right)^7=2^{42}\)
\(16^{12}=\left(2^4\right)^{12}=2^{48}\)
Mà \(2^{42}< 2^{48}\Rightarrow63^7< 64^7< 16^{12}\)=) \(63^7< 16^{12}\)
b) \(17^{14}\)và \(31^{11}\)
Có \(17^{14}>16^{14}=\left(2^4\right)^{14}=2^{56}\)
\(31^{11}< 32^{11}=\left(2^5\right)^{11}=2^{55}\)
Vì \(2^{56}>2^{55}\Rightarrow17^{14}>16^{14}>32^{11}>31^{11}\)
=) \(17^{14}>31^{11}\)
c) \(2^{67}\)và \(5^{21}\)
Có \(5^{21}< 8^{21}=\left(2^3\right)^{21}=2^{63}\)
Vì \(2^{67}>2^{63}\Rightarrow2^{67}>8^{21}>5^{21}\)
=) \(2^{67}>5^{21}\)

\(201^{60}=\left(201^4\right)^{15}=1944810000^{15}\)

\(398^{45}=\left(398^3\right)^{15}=63044792^{15}\)

Do \(1944810000>63044792\)

\(\Rightarrow1944810000^{15}>63044792^{15}\)

\(\Rightarrow201^{60}>398^{45}\)

Ta có:

\(201^{60}>200^{60};398^{45}< 400^{45}\)

\(200^{60}=\left(2.100\right)^{60}=2^{60}.100^{60}=2^{60}.\left(10^2\right)^{60}\)

\(=2^{60}.10^{120}=2^{60}.10^{30}.10^{90}\)

\(400^{45}=\left(2.100\right)^{45}=2^{45}.100^{45}=2^{45}.\left(10^2\right)^{45}\)

\(=2^{45}.10^{90}\)

Mà \(2^{60}.10^{30}.10^{90}>2^{45}.10^{90}\)

\(\Rightarrow200^{60}>400^{45}\)

\(\Rightarrow201^{60}>200^{60}>400^{45}>398^{45}\)

\(\Rightarrow201^{60}>398^{45}\)

`#3107`

\(201^{60}\text{ và }398^{45}\)

Ta có:

\(201^{60}=\left(201\right)^{15\cdot4}=\left(201^4\right)^{15}=1632240801^{15}\)

\(398^{45}=\left(398\right)^{15\cdot3}=\left(398^3\right)^{15}=63044792^{15}\)

Vì `63044792 < 1632240801 \Rightarrow`\(1632240801^{15}< 63044792^{15}\)

\(\Rightarrow201^{60}>398^{45}\)

Vậy, \(201^{60}>398^{45}.\)

27¹¹=(3³)¹¹= 3^3.11=3³³

81⁸= (3⁴)⁸=3^4.8=3³²

Vì: 3³³ > 3³² (33>32)

=> 27¹¹ > 81⁸

ta có :\(27^{11}=\left(3^3\right)^{11}=3^{33}\)

lại có :\(81^8=\left(3^4\right)^8=3^{32}\)

vì \(3^{33}>3^{32}\)=>\(27^{11}>81^8\)

Bài này ko cần trung gian

mk ko biết giai thông cảm

63^15<34^18

\(8^5=\left(2^3\right)^5=2^{15}=2.2^{14}\)

\(3.4^7=3.\left(2^2\right)^7=3.2^{14}\)

Vì 2 < 3 nên 8⁵ < 3 . 4⁷

8^5<3.4^7

17¹⁵ và 2⁵⁹

ta có:

17¹⁵>16¹⁵ ; 16¹⁵= (2⁴)¹⁵=2⁶⁰

Vì 2⁶⁰> 2⁵⁹=>16¹⁵>2⁵⁹

=>17¹⁵>2⁵⁹

Ta co : \(3^{500}\&7^{300}\)

\(\Rightarrow3^{500}=\left(3^5\right)^{100}=243^{100}\)

\(\Rightarrow7^{300}=\left(7^3\right)^{100}=343^{100}\)

Ta thay \(243^{100}

3^500=(3^5)^100=243^100

7^300=(7^3)^100=343^100

3⁵⁰⁰ = 3^5.100 = ( 3⁵)¹⁰⁰ 

7³⁰⁰ = 7^3.100 = ( 7³)¹⁰⁰ 

Vì 3⁵ < 7³ nên => 3⁵⁰⁰ < 7³⁰⁰ 

a/ 63¹⁵ < 64¹⁵ = (2⁶)¹⁵ = 2⁹⁰ (1)

34¹⁸ > 32¹⁸ = (2⁵)¹⁸ = 2⁹⁰ (2)

Từ (1) và (2) => 63¹⁵ < 34¹⁸

b/ 83⁹ > 81⁹ = (3⁴)⁹ = 3³⁶ (1)

26¹² < 27¹² = (3³)¹² = 3³⁶ (2)

Từ (1) và (2) => 83⁹ > 26¹²

Bài làm

63¹⁵ = 63^5.3 = ( 63⁵ )³ = 992 436 543³

34¹⁸ = 34^6.3 = ( 34⁶ )³ = 1 544 804 416 ³

Vì : 992 436 543³ < 1 544 804 416³

Nên : 63¹⁵ < 26¹⁸

83⁹ = 83^3.3 = ( 83³ )³ = 571 787³

26¹² = 26^{4.3 =} ( 26⁴ )³ = 456 978³

Vì : 571 787³ > 456 978³

Nên : 83⁹ > 26¹²