Tính bằng cách thuận tiện nhất:4/5x3/7+4/5+6/7x6/7-4/5x4/14
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
Tk mình đi mọi người mình bị âm nè!
ai tk mình mình tk lại cho!!!
4/5 * ( 3/7 + 4/5 - 4/14 )
rồi bạn tính tiếp đi nhé !
Nếu không thính thì bạn ni đổi đi nhé !
![](https://rs.olm.vn/images/avt/0.png?1311)
= 4/5 x ( 3/7 + 6/7 - 4/14 )
= 4/5 x ( 3/7 + 6/7 - 2/7 )
= 4/5 x 7/7
= 4/5
![](https://rs.olm.vn/images/avt/0.png?1311)
\(\dfrac{4}{5}\times\dfrac{3}{7}\times\dfrac{4}{5}\times\dfrac{6}{7}\times\dfrac{4}{14}=\dfrac{4}{5}\times\dfrac{3}{7}+\dfrac{4}{5}\times\dfrac{6}{7}-\dfrac{4}{5}\times\dfrac{2}{7}=\dfrac{4}{5}\times\left(\dfrac{6}{7}+\dfrac{3}{7}-\dfrac{2}{7}\right)=\dfrac{4}{5}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
=4/5 * (3/7+6/7-4/14)
=4/5*(6/14+12/14-4/14)
=4/5*12/14
=48/70
nha ban
![](https://rs.olm.vn/images/avt/0.png?1311)
1,
a, \(x\)x 124= 4829-365
\(x\)x 124 = 4464
\(x\)= 4464 :124
\(x\)= 36.
b,\(x\)x 137 = 25 x 3
\(x\)x 137 = 75
\(x\)= \(\frac{75}{137}\)
2,
\(\frac{4}{5}\)x\(\frac{3}{7}+\frac{4}{5}\)x\(\frac{6}{7}-\frac{4}{5}\)x\(\frac{4}{10}\)
=\(\frac{4}{5}\)x\(\left(\frac{3}{7}+\frac{6}{7}-\frac{4}{10}\right)\)=\(\frac{4}{5}\)x\(\frac{31}{35}\)\(\frac{124}{175}\)
\(\text{Bài }1\text{ : Tìm }x\text{ : }\)
\(a,\text{ }x\text{ x }124=4829-365\)
\(x\text{ x }124=4464\)
\(x=4464\text{ : }124\)
\(x=36\)
\(b,\text{ }x\text{ x }137=25\text{ x }3\)
\(x\text{ x }137=75\)
\(x=75\text{ : }137\)
\(x=\frac{75}{137}\)
\(\text{Bài }2\text{ : Tính bằng cách thuận tiện nhất : }\)
\(\frac{4}{5}\text{ x }\frac{3}{7}+\frac{4}{5}\text{ x }\frac{6}{7}-\frac{4}{5}\text{ x }\frac{4}{10}\)
\(=\frac{4}{5}\text{ x }\left(\frac{3}{7}+\frac{6}{7}-\frac{4}{10}\right)\)
\(=\frac{4}{5}\text{ x }\left(\frac{9}{7}-\frac{4}{10}\right)\)
\(=\frac{4}{5}\text{ x }\frac{31}{35}\)
\(=\frac{124}{175}\)
![](https://rs.olm.vn/images/avt/0.png?1311)
a) 145 + 86 + 14 + 55 = ( 145 + 55 ) + (86 + 14 )
= 200 + 100
= 300
b) 1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = ( 1+9 +2 + 8) + ( 3 + 7 + 4 + 6 ) + 5
= 20 + 20 + 5
= 45
![](https://rs.olm.vn/images/avt/0.png?1311)
A =\(\frac{2}{5}\times\frac{4}{7}+\frac{3}{5}\times\frac{4}{7}\) B = \(\frac{17}{13}\times\frac{12}{17}-\frac{4}{13}\times\frac{12}{17}\) C = \(\frac{9}{14}:\frac{6}{7}+\frac{5}{14}:\frac{6}{7}\) D =\(\frac{9}{12}:\frac{7}{9}\times\frac{12}{19}\)
= \(\frac{4}{7}\times\left(\frac{2}{5}+\frac{3}{5}\right)\) =\(\left(\frac{17}{13}-\frac{4}{13}\right)\times\frac{12}{17}\) = \((\frac{9}{14}+\frac{5}{14}):\frac{6}{7}\) = \(\frac{9}{12}\times\frac{9}{7}\times\frac{12}{19}\)
=\(\frac{4}{7}\times1\) = \(1\times\frac{12}{17}\) = \(1:\frac{6}{7}\) = \(\frac{9\times9\times12}{12\times7\times19}\)
=\(\frac{4}{7}\) = \(\frac{12}{17}\) =\(\frac{7}{6}\) = \(\frac{9\times9}{7\times19}=\frac{81}{133}\)
4/5x3/7+4/5+6/7x6/7-4/5x4/14
= ( 3/7 + 6/7 + 4/14) x 4/5
= 11/7 x 4/5
= 44/35
44/35