Ta có: 3^48=3^4*14=81^12

4^36=4^3*12=64^12

Vì 81>64 nên 81^12>64^12 hay 3^48>4^36

a: Ta có: \(A=\frac59+\left(-\frac57\right)+\left(-\frac{20}{48}\right)+\frac{8}{12}+\left(-\frac{21}{48}\right)\)

\(=\frac59-\frac57-\frac{41}{48}+\frac{32}{48}\)

\(=\frac{35-45}{63}-\frac{9}{48}=\frac{-10}{63}-\frac{3}{16}=\frac{-160-189}{63\cdot16}=\frac{-349}{1008}\)

b: \(B=\left(-\frac59\right)+\frac{8}{15}+\left(-\frac{2}{11}\right)+\left(\frac{4}{-9}\right)+\frac{2}{45}\)

\(=\left(-\frac59-\frac49\right)+\frac{8}{15}+\frac{2}{45}-\frac{2}{11}\)

\(=-1-\frac{2}{11}+\frac{24}{45}+\frac{2}{45}=-\frac{13}{11}+\frac{26}{45}=\frac{-13\cdot45+26\cdot11}{11\cdot45}=\frac{-299}{495}\)

c: \(\frac{1}{11}>\frac{1}{20};\frac{1}{12}>\frac{1}{20};\ldots;\frac{1}{20}=\frac{1}{20}\)

Do đó: \(\frac{1}{11}+\frac{1}{12}+\cdots+\frac{1}{20}>\frac{1}{20}+\frac{1}{20}+\cdots+\frac{1}{20}\)

=>S>10/20

=>S>1/2

Câu 1: 3^23  >    5^12

Câu 2: 3^36 < 2^8.11^4

M = 12 - ( - 5 )                          N = ( -3 ) - 20

M = 17                                     N = -23

=> M > N 

nha bn

M = 12 - (15 - 20) = 12 - (-5) = 17

N = 12 - 15 - 20 = (-3) - 20 = -23

Vậy M > N

\(\dfrac{-12}{310}\text{ }và\text{ }\dfrac{8}{-36}\\ Có:310=2\cdot5\cdot31\\ 36=2^2\cdot3^2\\ \Rightarrow BCNN_{\left(310;36\right)}=2^2\cdot3^2\cdot5\cdot31=5580\\ \Rightarrow\dfrac{-12}{310}=\dfrac{-216}{5580}\\ \dfrac{8}{-36}=\dfrac{1240}{-5580}\\ mà\text{ }\dfrac{-216}{5580}>\dfrac{1240}{-5580}\\ Vậy\text{ }\dfrac{-12}{310}>\dfrac{8}{-36}\)

Ta có:
\(3^{20}\cdot2^{29}< 3^{20}\cdot2^{40}=3^{20}\cdot4^{20}=\left(3\cdot4\right)^{20}=12^{20}\)

Vậy\(12^{20}>3^{20}\cdot2^{39}\)

Ủng hộ mk nhá

đề bài đưa ra là so sánh 12²⁰ và 3²⁰ x 2³⁹

vậy bài làm là :

12²⁰ < 3²⁰ x 2³⁹ 

    Đáp số :.................

AI K MK MK K LẠI

a, \(\frac{-12}{18}\)= \(\frac{-2}{3}\); \(\frac{-21}{35}\)= \(\frac{-3}{5}\)

  Ta quy đồng mẫu của 2 ps bằng 15

  \(\frac{-2}{3}\)= \(\frac{-2.5}{15}\)= \(\frac{-10}{15}\); \(\frac{-3}{5}\)= \(\frac{-3.3}{15}\)= \(\frac{-9}{15}\)

=> \(\frac{-12}{18}\)< \(\frac{-21}{35}\)( vì ( - 10 ) < ( - 9 ) )

những bài khác cũng như vậy nha

nhớ ủng hộ mik nữa