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4 x 2 x 5 = ?
Cách 1: 4 x 2 x 5 = (4 x 2) x 5 = 8 x 5 = 40
Cách 2: 4 x 2 x 5 = 4 x (2 x 5) = 4 x 10 = 40
7 x 2 x 3 = ?
Cách 1: 7 x 2 x 3 = (7 x 2) x 3 = 14 x 3 = 42
Cách 2: 7 x 2 x 3 = 7 x (2 x 3) = 7 x 6 = 42
6 x 3 x 3 = ?
Cách 1: 6 x 3 x 3 = (6 x 3) x 3 = 18 x 3 = 54
Cách 2: 6 x 3 x 3 = 6 x (3 x 3) = 6 x 9 = 54
6 x 2 x 4 = ?
Cách 1: 6 x 2 x 4 = (6 x 2) x 4 = 12 x 4 = 48
Cách 2: 6 x 2 x 4 = 6 x (2 x 4) = 6 x 8 = 48
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321 x 3 + 321 x 5 + 321 x 2
= 321 x (3 + 5 + 2)
= 321 x 10
= 3 210.
321 x 3 + 321 x 5 + 321 x 2
= 321 x (3 + 5 + 2)
= 321 x 10
= 3210
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`(3xx4xx7)/(5xx3xx4)=7/5`
`(2xx5xx6xx8)/(6xx2xx8xx9)=5/9`
`(4xx5xx6)/(3xx10xx8)= (4xx5xx6)/(3xx5xx2xx4xx2)= 6/(3xx2xx2)= 6/(6xx2)=1/2`
\(a,\dfrac{3\times4\times7}{5\times3\times4}=\dfrac{7}{5}\)
\(b,\dfrac{2\times5\times6\times8}{6\times2\times8\times9}=\dfrac{5}{9}\)
\(c,\dfrac{4\times5\times6}{3\times10\times8}=\dfrac{2}{4}=\dfrac{1}{2}\)
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a)1440:40 =36
b)205 x 13 =2665
c)2057
d)36 x 25 x 4 =3600
18 x 24 :9 =48
41 x 2 x 8 x 5 =3280
215 x 86 + 215 x 14 =21500
53 x 128 - 43 x 128 =1408
2/3 x 4/7 =8/21
2 x 3 x 4 / 2 x 3 x 4 x 5 =24/120
1 x 2 x 3 x 4 / 5 x 6 x 7 x 8=24/1680
x : 7/11 = 22
x =22 x 7/11
x =14
2/7 * x =2/3
x = 2/7 :2/3
x = 20/21
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a) \(\frac{2}{3}.\frac{3}{4}.\frac{4}{5}:\frac{1}{5}\) b) \(\frac{1.2.3.4}{5.6.7.8}\)
\(=\frac{1}{2}.\frac{4}{5}:\frac{1}{5}\) \(=\frac{24}{1680}\)
\(=\frac{2}{5}.5\) \(=70\)
\(=2\)
c) \(\frac{2}{5}.\frac{3}{4}.\frac{5}{6}:\frac{3}{4}\)
\(=\frac{3}{10}.\frac{5}{6}.\frac{4}{3}\)
\(=\frac{1}{4}.\frac{4}{3}\)
\(=\frac{1}{3}\)
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a) 720 : ( x . 2 + x . 3 ) = 3.2
720 : ( x . 2 + x.3 ) = 6
( x .2 + x.3 ) = 720 : 6
x.2+x.3 = 120
x . ( 2 + 3 ) = 120
x . 5 = 120
x = 120 : 5
x = 24
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\(\frac{2}{3}\cdot\frac{3}{4}\cdot\frac{4}{5}:\frac{1}{5}\)
\(=\frac{1}{2}\cdot4\)
\(=2\)
\(\frac{1\cdot2\cdot3\cdot4}{5\cdot6\cdot7\cdot8}=\frac{1\cdot1\cdot3\cdot1}{5\cdot3\cdot7\cdot2}=\frac{1\cdot1\cdot1\cdot1}{5\cdot1\cdot7\cdot2}=\frac{1}{70}\)
\(\frac{2}{5}\cdot\frac{3}{4}\cdot\frac{5}{6}:\frac{3}{4}\)
\(=\frac{2}{5}\cdot\frac{5}{6}\cdot\frac{3}{4}:\frac{3}{4}\)
\(=\frac{1}{3}\cdot1\)
\(=\frac{1}{3}\)
\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}\div\frac{5}{1}\)
\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}\times\frac{5}{1}\)
\(=\frac{2}{1}=2\)
Các phần khác tương tự nhé em , nếu ko biết giải qua tin nhắn chị gửi cho
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\frac{2}{3}\times\frac{3}{4}\times\frac{4}{5}:\frac{1}{5}\)
\(=\frac{1}{2}\times\frac{4}{5}:\frac{1}{5}\)
\(=\frac{2}{5}:\frac{1}{5}\)
\(=2\)
a) 2/3 x 3/4 x 4/5 : 1/5
= 1/2 x 4
= 2
b) 1 x 2 x 3 x 4/5 x 6 x 7 x 8
= 2 x 3 x 24/5 x 56
= 6 x 72/5 x 56
= 432/5 x 56
= 24192/5
c) 2/5 x 3/4 x 5/6 : 3/4
= 3/10 x 10/9
= 1/3