1) 1/3 x 1/2 x 3/7 = 3/42 = 1/14

2) 5/4 x 1/3 +1/7 = 5/12 + 1/7 = 35/84 + 12/84 = 47/84

3) 8 x ( 8/9 - 2/3 ) = 8 x 2/9 = 16/9

4) 5/6 x 48/20 x 1/2 = 240/240 = 1

5) ( 2/5 + 3/4 ) + 8 = 23/20 + 8 = 23//20 + 160/20 = 183/20

6) 10 x ( 1/2 - 1/5 ) = 10 x 3/10 = 10/1 x 3/10 = 30/10 = 3

=1013040.1/100.25/12

=21105

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

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

= 10+10+10+10+10

=50

Hok tốt !!!!!

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

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

=10+10+10+10+5

=45

Xin lỗi mik nhìn nhầm 

=45

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

2

= 2

\(A=\left(6-\frac{2}{3}+\frac{1}{2}\right)-\left(5+\frac{5}{3}-\frac{3}{2}\right)-\left(3-\frac{7}{3}+\frac{5}{2}\right)\)

\(=6-\frac{2}{3}+\frac{1}{2}-5-\frac{5}{3}+\frac{3}{2}-3+\frac{7}{3}-\frac{5}{2}\)

\(=6-5-3+\left(\frac{-2}{3}+\frac{-5}{3}+\frac{7}{3}\right)+\left(\frac{1}{2}+\frac{3}{2}-\frac{5}{2}\right)\)

\(=-2+0+\frac{-1}{2}=\frac{-5}{2}\)

Thank you!

`5/3 + 1/5 : 3/4`

`= 5/3 + 1/5 xx 4/3`

`= 5/3 + 4/15`

`= 25/15 +4/15`

`= 29/15`

5/3 + 1/5 : 3/4

= 5/3 + 1/5 x 4/3

= 5/3 + 4/15

= 25/15 + 4/15

=29/15

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