ko ai bit thi thui ko tra loi thi cam

nhanh lên

a: \(=\dfrac{3}{22}\cdot22\cdot\dfrac{3}{11}=3\cdot\dfrac{3}{11}=\dfrac{9}{11}\)

b: \(=\dfrac{5}{6}\cdot\dfrac{2}{5}=\dfrac{1}{3}\)

c: \(=\dfrac{17}{21}\left(\dfrac{3}{5}+\dfrac{2}{5}\right)=\dfrac{17}{21}\)

a : = \(\dfrac{3}{22}\). 22 . \(\dfrac{3}{11}\) = 3 . \(\dfrac{3}{11}\) = \(\dfrac{9}{11}\)

b : = \(\dfrac{5}{6}\). \(\dfrac{2}{5}\) = \(\dfrac{1}{3}\)

c: = \(\dfrac{17}{21}\)(\(\dfrac{3}{5}\) + \(\dfrac{2}{5}\)   ) = \(\dfrac{17}{21}\)

ban giai ho minh

3/22 x 3/11 x 22=

c1:\(\frac{3\times3\times22}{22\times11}=\frac{9}{11}\)                              c2:\(\frac{9}{242}\times22=\frac{9}{11}\)

( 1/2 + 1/3 ) x 2/5=

c1:\(\frac{5}{6}\times\frac{2}{5}=\frac{1}{3}\)                                    c2:\(\frac{1}{2}\times\frac{2}{5}+\frac{1}{3}\times\frac{2}{5}=\frac{1}{5}+\frac{2}{15}=\frac{1}{3}\)

C1: 3/22 x 3/11 x 22

= 9 x 22/22 x 11 = 198/242=9/11

C2: 3/22 x 3/11 x 22

= 3 x 3 x 22/22 x 11 x 1 = 3 x 3/ 11 x 1 = 9/11

a) 2/7 X x = 2/3 

X = 2/3 : 2/7 

X = 7/3

b) 2/5 : x = 1/3

X =  2/5 : 1/3

X = 6/5

c) x : 7/11 = 22

X = 22 x 7/11

X = 14

d) 1/2 : x = 5

X = 1/2 : 5

X = 1/10

a) x = 2/3 : 2/7

x = 7/3

vậy x =...

b) x = 2/5 : 1/3

x = 6/5

vậy x =..

c) x = 22 x 7/11

x = 14

vậy x =...

d) x = 1/2 : 5

x = 1/10

vậy x =...

a) \(\dfrac{2}{7}\times x=\dfrac{2}{3}\)

            \(x=\dfrac{2}{3}\div\dfrac{2}{7}\)

           \(x=\dfrac{7}{3}\)

b) \(\dfrac{2}{5}:x=\dfrac{1}{3}\)

          \(x=\dfrac{2}{5}:\dfrac{1}{3}\)

          \(x=\dfrac{6}{5}\)

c) \(x:\dfrac{7}{11}=22\)

    \(x=22\times\dfrac{7}{11}\)

    \(x=\dfrac{154}{11}\)

   \(x=14\)

d) \(\dfrac{1}{2}:x=5\)

          \(x=\dfrac{1}{2}:5\)

          \(x=\dfrac{1}{10}\)

Chọn đáp án B

\(x-\frac{10}{3}=\frac{7}{15}.\frac{3}{5}\)

\(x-\frac{10}{3}=\frac{7}{25}\)

\(x=\frac{7}{25}+\frac{10}{3}=\frac{271}{75}\)

Vậy x = 271/75

\(x-\frac{10}{3}\)\(=\)\(\frac{7}{15}\)\(.\)\(\frac{3}{5}\)

\(x-\frac{10}{3}\)\(=\)  \(\frac{7}{25}\)

\(x\)             \(=\)\(\frac{7}{25}\)\(+\)\(\frac{10}{3}\)

\(x\)                 \(=\)    \(\frac{271}{75}\)

Trả lời:

x-10/3=7/15.3/5

x-10/3=7/25

x=10/3+7/25

x=271/75

x+3/22=27/121.11/9

x+3/22=3/11

x=3/11-3/22

x=3/22

1/5:x=1/2

x=1/5:1/2

x=1/5.2

x=2/5

3/5+2/5.x=1

2/5.x=1-3/5

2/5.x=2/5

x=2/5:2/5

x=1