a) 5/16 > -9/24

b) 5/6>-1/2

c)-7/12<3/4

a, 5/16 > -9/24

 b, 5/6 > -1/2 

c, -7/12 < 3/4

a: 5/16>0>-9/24

b: 5/6>0>-1/2

c: -7/12<0<3/4

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

63¹⁵ <64¹⁵

34¹⁸<36¹⁸

64¹⁵=8³⁰ =(2.4)³⁰

36¹⁸=6³⁶

^{sau đó các bạn tự giải}

Ta có :

26⁹ < 27⁹ = ( 3³ )⁹ = 3²⁷

83⁷ > 81⁷ = ( 3⁴ )⁷ = 3²⁸

MÀ 26⁹ < 3²⁷ < 3²⁸ < 83⁷ = > 26⁹ < 83⁷

Vậy 26⁹ < 83⁷

help

a: \(\dfrac{25}{26}=1-\dfrac{1}{26}\)

\(\dfrac{50}{51}=1-\dfrac{1}{51}\)

mà \(-\dfrac{1}{26}< -\dfrac{1}{51}\)

nên \(\dfrac{25}{26}< \dfrac{50}{51}\)

b: \(\dfrac{149}{157}=1-\dfrac{8}{157}\)

\(\dfrac{449}{457}=1-\dfrac{8}{457}\)

mà \(-\dfrac{8}{157}>-\dfrac{8}{457}\)

nên \(\dfrac{149}{157}>\dfrac{449}{457}\)

(-23)^9 < (-16)^3

(-32)^9<(-16)^3 vì

(-32)^9= ((-2)^5)^9= (-2)^45

(-16)^3= ((-2)^4)^3= (-2)^12

Vì (-2)^45<(-2)^12=> (-32)^9<(-16)^3

\(\left(-32\right)^9=\left(-2^5\right)^9=\left(-2\right)^{45}\)

\(\left(-16\right)^3=\left(-2^4\right)^3=\left(-2\right)^{12}=2^{12}>-2^{45}\)

\(\Rightarrow\left(-16\right)^3>\left(-32\right)^9\)