\(\dfrac{1}{5}\times\dfrac{4}{7}+\dfrac{3}{7}\times\dfrac{1}{5}-\dfrac{1}{5}\)

\(=\dfrac{4}{35}+\dfrac{3}{35}-\dfrac{1}{5}\)

\(=\dfrac{7}{35}-\dfrac{1}{5}\)

\(=\dfrac{1}{5}-\dfrac{1}{5}\)

\(=0\)

0

tíc cho mình nha

2/3 - 7/24 = 3/8 

\(\frac{2}{3}-\left(\frac{1}{6}+\frac{1}{8}\right)\)=\(\frac{16}{24}-\left(\frac{4}{24}+\frac{3}{24}\right)\)=\(\frac{16}{24}-\frac{7}{24}=\frac{9}{24}=\frac{3}{8}\)

\(a,\dfrac{9}{5}+\dfrac{2}{5}\times\dfrac{4}{6}=\dfrac{9}{5}+\dfrac{4}{15}=\dfrac{27}{15}+\dfrac{4}{15}=\dfrac{31}{15}\\ b,\dfrac{3}{8}\times2-\dfrac{6}{7}\times\dfrac{1}{3}=\dfrac{3}{4}-\dfrac{2}{7}=\dfrac{21}{28}-\dfrac{8}{28}=\dfrac{13}{28}\)

A)=9/5 + 4/15

=27/15+4/15

=31/15

B)=3/4-2/14

=36/28-4/28

=32/28=?

  1/2x1/3+1/3x1/4+1/4x1/5+1/5x1/6+1/6x1/7+1/7x1/8+1/8x1/9

=7/18

\(=\dfrac{3}{7}\times\left(\dfrac{1}{5}+\dfrac{2}{3}-\dfrac{1}{8}\right)\\ =\dfrac{3}{7}\times\left(\dfrac{24}{5\times24}+\dfrac{2\times40}{3\times40}-\dfrac{15}{8\times15}\right)\\ =\dfrac{3}{7}\times\left(\dfrac{24+80-15}{120}\right)\\ =\dfrac{3}{7}\times\dfrac{89}{120}\\ =\dfrac{89}{280}\)

\(\dfrac{3}{7}\times\dfrac{1}{5}+\dfrac{2}{3}\times\dfrac{3}{7}-\dfrac{3}{7}\times\dfrac{1}{8}\)
\(=\dfrac{3}{7}\times\left(\dfrac{1}{5}+\dfrac{3}{7}-\dfrac{1}{8}\right)\)
\(=\dfrac{3}{7}\times\dfrac{56+120-35}{280}\)
\(=\dfrac{3}{7}\times\dfrac{141}{280}\)
\(=\dfrac{423}{1960}\)

1-3/5

=5/5-3/5

=2/5

3/5*4/7

=12/35

2/5 >12/35

nho ****

= -97/1176 ^{lớp 4 học số âm à???}

-97/1176 

-97/1176 

a) C1:

= 11/10 x 4/5 = 44/50 = 22/25

C2:

= 3/5 x 4/5 + 1/2 x 4/5 = 12/25 + 2/5 = 22/25

b) C1:

= 2/5 x (3/7 + 4/7) = 2/5 x 1 = 2/5

C2:

= 6/35 + 8/35 = 14/35 = 2/5

a)(3/5+1/2)x4/5

= \(\left(\dfrac{6}{10}+\dfrac{5}{10}\right)\times\dfrac{4}{5}=\dfrac{11}{10}\times\dfrac{4}{5}=\dfrac{22}{25}\)

\(=\dfrac{3}{5}\times\dfrac{4}{5}+\dfrac{1}{2}\times\dfrac{4}{5}=\dfrac{12}{25}+\dfrac{2}{5}=\dfrac{22}{25}\)

b)2/5x3/7+2/5x4/7

\(=\dfrac{6}{35}+\dfrac{8}{35}=\dfrac{14}{35}=\dfrac{2}{5}\)

\(=\dfrac{2}{5}\times\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{2}{5}\times1=\dfrac{2}{5}\)

\(\)

vvvvvvvvvvvvvvvv

8/13+4/9+1/3+5/13+3=

(8/13+5/13)+(4/9+3/9)+3=

1+7/9+3=4 7/9

8/5x4/7+4/7x2/5=

4/7x(8/5+2/5)

=4/7x2=8/7

a) kết quả bằng  43/9

b) hiện tại chưa tính ra