\(\frac{1}{2}+\frac{2}{4}+\frac{3}{6}+\frac{4}{8}+\frac{5}{10}+\frac{6}{12}\)

\(=\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}+\frac{1}{2}\)

\(=6\times\frac{1}{2}=3\)

= 3 nhé

tích mik nha

\(\dfrac{1}{3}+\dfrac{1}{6}+\dfrac{4}{3}+\dfrac{2}{6}+\dfrac{2}{3}+\dfrac{5}{6}\)

\(=\left(\dfrac{1}{3}+\dfrac{4}{3}+\dfrac{2}{3}\right)+\left(\dfrac{1}{6}+\dfrac{2}{6}+\dfrac{5}{6}\right)\)

\(=\dfrac{7}{3}+\dfrac{8}{6}\)\(=\dfrac{7}{3}+\dfrac{4}{3}\)

\(=\dfrac{11}{3}\)

5/6 nhân(2/3 cộng 1/3) cộng 5/3
5/6 nhân 1 cộng 5/3
5/6 cộng 5/3
5/2

`4/6 xx 1/5 + 4/6 xx 3/5 + 2/6 xx 4/5`

`= 4/6 xx (1/5 + 3/5) + 2/6 xx 4/5`

`= 4/6 xx 4/5 + 2/6 xx 4/5`

`= (4/6 +2/6) xx 4/5`

`= 6/6 xx 4/5`

`=1 xx 4/5`

`=4/5`

Em cảm ơn

Giải đấy đủ giúp mình với 

a: =8/15x1/4=2/15

b: \(=\dfrac{5}{3}\cdot\dfrac{4}{5}\cdot\dfrac{6}{7}=\dfrac{24}{21}=\dfrac{8}{7}\)

c: \(=\dfrac{2}{5}\left(\dfrac{3}{7}+\dfrac{4}{7}\right)=\dfrac{2}{5}\)

\(\frac{1}{2}-\frac{2}{5}+\frac{1}{3}-\frac{3}{5}+\frac{1}{6}\)

\(=\frac{3}{6}-\frac{2}{5}+\frac{2}{6}-\frac{3}{5}+\frac{1}{6}\)

\(=\left(\frac{3}{6}+\frac{2}{6}+\frac{1}{6}\right)+\left(\frac{2}{5}+\frac{3}{5}\right)\)

\(=1+1\)

\(=2\)

@muối

1/2 - 2/5 + 1/3 - 3/5 + 1/6

= 1/2 + 1/3 + 1/6 - 2/5 - 3/5

= (1/2 + 1/3 + 1/6) - (2/5 + 3/5)

= 1 - 1 

= 0

Chúc bạn học tốt.

😁😁😁

1/2 - 2/5 + 1/3 - 3/5 + 1/6 = 0

Bài 1:

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

=(1+9)+(2+8)+(3+7)+(4+6)+(5+5)

=10+10+10+10+10

=50

Bài 2:

3*2*2*2*10*10*10*10

=3*(2*3)*(10*4)

=3*6*40

=640

hok tốt (đúng chưa vậy)

Bài 1 :

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

= ( 1 + 9 ) + ( 2 + 8 ) + ( 3 + 7 ) + ( 4 + 6 ) + ( 5 + 5 )

= 10 + 10 + 10 + 10 + 10

= 50

  BÀI 1. TÍNH BẰNG CÁCH THUẬN TIỆN NHẤT 

1+2+3+4+5+5+6+7+8+9 = 

=(1+9)+(2+8) +(3+7)+(4+6)+5

= 10+10+10+10+5

=45

BÀI 2. TÍNH BẰNG CÁCH THUẬN TIỆN NHẤT

3 x 2 x 2 x 2 x 10 x 10 x10 x 10 = 240 000

\(5\dfrac{3}{4}:3+2\dfrac{1}{4}\times\dfrac{1}{3}-\dfrac{1}{8}=\left(5\dfrac{3}{4}+2\dfrac{1}{4}\right)\times\dfrac{1}{3}-\dfrac{1}{8}\\ =8\times\dfrac{1}{3}-\dfrac{1}{8}=\dfrac{8}{3}-\dfrac{1}{8}=\dfrac{61}{24}\\ ----\\ \dfrac{3}{5}:\dfrac{5}{6}:\dfrac{6}{7}:\dfrac{7}{8}+\dfrac{2}{5}+\dfrac{23}{35}\\ =\dfrac{3}{5}\times\dfrac{6}{5}\times\dfrac{7}{6}\times\dfrac{8}{7}+\dfrac{2}{5}+\dfrac{23}{35}=\dfrac{18}{25}\times\dfrac{4}{3}+\dfrac{2}{5}+\dfrac{23}{35}=\dfrac{353}{175}\)