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bài này lớp 5 mè

(27x+6)÷3-11=9

=> (27x+6)÷3=20

=> 27x + 6 = 60

=> 27x = 54

=> x = 2

(27.x + 6) : 3 - 11 = 9

(27x + 6) : 3 = 9 + 11

(27x + 6) : 3 = 20

27x + 6 = 20 . 3

27x + 6 = 60

27x = 60 - 6

27x = 54

x = 54 : 27

x = 2

(27.x + 6) : 3 - 11 = 9

(27.x + 6) : 3 = 9 + 11

(27.x + 6) : 3 = 20

27.x + 6 = 20.3

27.x + 6 = 60

27.x = 60 - 6

27.x = 54

x = 54 : 27

x = 2

a: Ta có: \(\left(-\frac57-\frac79+\frac{9}{11}-\frac{11}{13}\right)\cdot\left(3-\frac34\right)\)

\(=\left(-\frac{6435}{9009}-\frac{7007}{9009}+\frac{7371}{9009}-\frac{7623}{9009}\right)\cdot\frac94\)

\(=-\frac{13694}{9009}\cdot\frac94=\frac{-6847}{2}\cdot\frac{1}{1001}=\frac{-6847}{2002}\)

b: \(\left(\frac{10}{21}+\frac{14}{27}-\frac{6}{11}+\frac{22}{39}\right):\left(2-\frac23\right)\)

\(=\left(\frac{12870}{27027}+\frac{14014}{27027}-\frac{14742}{27027}+\frac{15246}{27027}\right):\frac43\)

\(=\frac{27388}{27027}\cdot\frac34=\frac{6847}{9009}\)

282 ban a

282 nhe ban

( 27x + 6) : 3 - 11 = 9

( 27x + 6) : 3 = 20

27x + 6 = 60

27x = 54

x = 2 

(27*x+6):3=9+11=20

27x+6=20 .3=60

27x=60-6=54

x=54:27

x=2

2: \(=\dfrac{-2}{75}+\dfrac{5}{39}=\dfrac{33}{325}\)

3: \(=\dfrac{6}{11}\left(\dfrac{4}{9}+\dfrac{5}{9}\right)=\dfrac{6}{11}\)

4: \(=\dfrac{7}{19}\left(\dfrac{5}{13}+\dfrac{8}{13}-1\right)=-2\cdot\dfrac{7}{19}=-\dfrac{14}{19}\)

5: \(=\dfrac{2}{7}\left(\dfrac{4}{23}-\dfrac{27}{23}+1\right)=0\)

6: \(=\dfrac{3}{8}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)+\dfrac{11}{8}=\dfrac{3}{8}+\dfrac{11}{8}=\dfrac{14}{8}=\dfrac{7}{4}\)

=88.57596425 nha bn.