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4-5/7=23/7
1/2:3=1/6
578,97x307=177743,79
266,22:34=7,83
4-5/7=28/5
1/2:3=1/6
578,97nhân307=177743.79
266,22:34=7.83
a, \(4-\frac{5}{7}=\frac{28}{7}-\frac{5}{7}=\frac{23}{7}\)
b,\(\frac{1}{2}\div3=\frac{1}{2}\times\frac{1}{3}=\frac{1}{6}\)
c,\(266,22\div34=\frac{13311}{50}\times\frac{1}{34}=\frac{783}{100}\)
d,\(20,57\times416=8557,12\)
Bài 1 : Tính
a) 4 - 5/7 = .....23/7.............
b) 1/2 : 3 = ......1/6........................
c) 266,22 : 34 = ..............7,83............
d) 7/9 + 9/10 = ......151/90...................
e) 3 và 1/2 : 2 và 1/4 = .....14/9...........
g) 21,76 x 2,05 =....44,608......................
h) 75,95 : 3,5 = .........21,7...................
i) 5/6 + 7/12 = .......17/12...................
k) 3 - 5/7 = .....16/7...................
Bài 1 : Tính
a) 4 - 5/7 = 23/7.
b) 1/2 : 3 = 1/6.
c) 266,22 : 34 = 783/100
d) 7/9 + 9/10 = 151/90
e) 3 và 1/2 : 2 và 1/4 = 3
g) 21,76 nhân 2,05 =.5576/125
h) 75,95 : 3,5 = 217/10
i) 5/6 + 7/12 = 97/102
k) 3 - 5/7 = 16/7
a) \(\frac{11}{15}+\frac{5}{7}+\frac{2}{7}+\frac{4}{15}=\left(\frac{11}{15}+\frac{4}{15}\right)+\left(\frac{5}{7}+\frac{2}{7}\right)\)
\(=2\)
b) \(\frac{5}{9}\times\frac{1}{2}\times\frac{5}{9}\times\frac{6}{4}=\frac{25}{81}\times\frac{3}{4}=\frac{25}{108}\)
c) \(\frac{7}{8}\div\frac{1}{2}+\frac{9}{8}\div\frac{1}{2}=\left(\frac{7}{8}+\frac{9}{8}\right)\div\frac{1}{2}\)
\(=2\div\frac{1}{2}=4\)
d) \(\frac{17}{10}+\frac{1}{2}-\frac{7}{10}=\left(\frac{17}{10}-\frac{7}{10}\right)+\frac{1}{2}\)
\(=1+\frac{1}{2}=\frac{3}{2}\)
a) \(\frac{11}{15}+\frac{5}{7}+\frac{2}{7}+\frac{4}{15}\)
\(=\left(\frac{11}{15}+\frac{4}{15}\right)+\left(\frac{5}{7}+\frac{2}{7}\right)\)
\(=1+1\)
\(=2\)
b) \(\frac{5}{9}.\frac{1}{2}.\frac{5}{9}.\frac{6}{4}\)
\(=\left(\frac{5}{9}\right)^2\left(\frac{1}{2}.\frac{6}{4}\right)\)
\(=\frac{25}{81}.\frac{3}{4}\)
\(=\frac{25}{108}\)
c) \(\frac{7}{8}:\frac{1}{2}+\frac{9}{8}:\frac{1}{2}\)
\(=\frac{7}{8}.2+\frac{9}{8}.2\)
\(=2\left(\frac{7}{8}+\frac{9}{8}\right)\)
\(=2.\frac{16}{8}\)
\(=2.2\)
\(=4\)
d) \(\frac{17}{10}+\frac{1}{2}-\frac{7}{10}\)
\(=\left(\frac{17}{10}-\frac{7}{10}\right)+\frac{1}{2}\)
\(=1+\frac{1}{2}\)
\(=\frac{2}{2}+\frac{1}{2}\)
\(=\frac{3}{2}\)
Dấu "." là dấu nhân nhé
\(\frac{1}{2.4}+\frac{1}{4.6}+\frac{1}{6.8}+...+\frac{1}{2016.2018}\)
\(=\frac{1}{2}.\left(\frac{2}{2.4}+\frac{2}{4.6}+...+\frac{2}{2016.2018}\right)\)
\(=\frac{1}{2}.\left(1-\frac{1}{4}+\frac{1}{4}-\frac{1}{6}+...+\frac{1}{2016}-\frac{1}{2018}\right)\)
\(=\frac{1}{2}.\left(1-\frac{1}{2018}\right)\)
\(=\frac{1}{2}.\frac{2017}{2018}\)
\(=\frac{2017}{4036}\)
\(x.\frac{2}{7}.\frac{3}{4}=\frac{5}{21}\)
\(\frac{3}{14}x=\frac{5}{21}\)
\(x=\frac{5}{21}:\frac{3}{14}\)
\(x=\frac{5}{21}.\frac{14}{3}\)
\(x=\frac{10}{9}\)
Vậy \(x=\frac{10}{9}\)
những câu bài 2 này là tìm x bình thường
a,(11/15+4/15)+(5/7+2/7)
=1+1
=2
b,5/9x(1/2+6/4)
=5/9x2
=10/9
c,1/2:(7/8+9/8)
=1/2:2
=1
d,(17/10-7/10)+1/2
=1+1/2
=3/2
a,=23/7
b,1/6
c,177743.79
d,78/200
Tính:
a, 4 - \(\frac{5}{7}\)= \(\frac{23}{7}\)
b, 12 : 3 = 4
c, 578,97 x 307 = 177743,79
d, 266,22 : 34 =7,83
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