\(11=\frac{77}{7}< \frac{78}{7}\Rightarrow-\frac{11}{3^7\cdot7^3}>-\frac{78}{3^7\cdot7^4}\)

\(\frac{-11}{3^7.7^3}>\frac{-78}{3^7.7^4}\)

bạn có thể ghi rõ ko

có - 11/3^7.7^3 =-77/3^7.7^4 rồi so sánh với -78/3^7.7^4 nhé :))

ai cứu với ạ

9+3.(-5)=9+(-15)= -6

\(\frac{-2}{15}\)-\(\frac{4}{25}\)=  \(\frac{-10}{75}\)-\(\frac{12}{75}\)= \(\frac{-22}{75}\)

\(\frac{-3}{5}\).  \(\frac{4}{11}\)+\(\frac{-3}{7}\).  \(\frac{7}{11}\)+   \(\frac{-3}{7}\)=  \(\frac{-12}{55}\)+  \(\frac{-21}{77}\)+   \(\frac{-3}{7}\)

                                                                    =   \(\frac{-84}{385}\)+\(\frac{-105}{385}\)+\(\frac{-165}{385}\)

                                                                    =  \(\frac{-354}{385}\)

a) 9+3.(-5) =9-15=-6

b) \(\frac{-2}{15}-\frac{4}{25}=\frac{-2.5}{75}-\frac{4.3}{75}=\frac{-10-12}{75}=\frac{-22}{75}\)

c) \(\frac{-3}{5}.\frac{4}{11}+\frac{-3}{7}.\frac{7}{11}+\frac{-3}{7}=\frac{-12}{55}+\frac{-21}{77}+\frac{-3}{7}=\frac{-12.7}{385}+\frac{-21.5}{385}+\frac{-21.55}{385}=\frac{-84-105-1155}{385}=\frac{-1344}{385}=\frac{-192}{5}\)

hi! hi! hk bit dug hk :)

2:

=>27:3^x=2*25-16-31=50-47=3

=>3^x=27/3=9

=>3^x=3^2

=>x=2

1:

b: \(=16\cdot55+16\cdot45-1\)

=16(55+45)-1

=1600-1

=1599

c: \(=\dfrac{1800}{49-\left[2\cdot\left(36-34\right)^3-5\right]}\)

\(=\dfrac{1800}{49-2\cdot2^3+5}=\dfrac{1800}{49-16+5}=\dfrac{1800}{38}\)=900/19

d: \(=\dfrac{5\cdot3^{11}\cdot2^{11}-3^{11}\cdot2^{11}}{2^{10}\cdot3^{10}\cdot2^2\cdot3+7\cdot2^{12}\cdot3^{12}}\)

\(=\dfrac{3^{11}\cdot2^{11}\left(5-1\right)}{2^{12}\cdot3^{11}\left(1+7\cdot3\right)}=\dfrac{1}{2}\cdot\dfrac{4}{1+21}=\dfrac{4}{22\cdot2}=\dfrac{1}{11}\)