\((3/7-2/7)+8/35=1/7+8/35=5/35+8/35=13/35\)

Chúc em học tốt

\(=\dfrac{3}{7}\cdot\left(\dfrac{4}{9}+\dfrac{5}{9}+1\right)=\dfrac{3}{7}\cdot2=\dfrac{6}{7}\)

\(=\dfrac{3}{7}\times\dfrac{4}{9}\times\dfrac{5}{9}\times\dfrac{3}{7}+\dfrac{3}{7}=\dfrac{3}{7}\times\left(\dfrac{4}{9}+\dfrac{5}{9}+1\right)=\dfrac{3}{7}\times2=\dfrac{6}{7}\)

=3/7 x (4/9 + 5/9) = 3/7 x1 =3/7

^{1/2 + 2/3 - 3/4 * 4/5 * 5/6 * 6/7 * 7/8 * 8/9 *...* 29/30 : 6/10}

^{= 1/2 + 2/3 - 1/10 : 6/10}

^{= 1/2 + 2/3 - 1/6}

^{= 1}

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

= 3/2 x   1

= 3/2

3/2 x ( 4/7 + 3/7 )

= 3/2 x 1

= 3/2

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

`3+1/9+3/9+2+5/9+3+2`

`= ( 3 +2+3+2) +(1/9+ 3/9 + 5/9)`

`= 10 + 9/9`

`=10 + 1`

`=11`

\(3+\dfrac{1}{9}+\dfrac{3}{9}+2+\dfrac{5}{9}+3+2\)

\(=3+\left(\dfrac{1}{9}+\dfrac{3}{9}+\dfrac{5}{9}\right)+2+3+2\)

\(=\left(3+2+3+2\right)+\dfrac{9}{9}\)

\(=10+1=11\)

18 phần11 nhân4 phần5 trừ7 phần11 nhân4 phần5 cộng9 phần3 nhân2 phần5

3228

3228 nhé em

thanks

a) 1/2

b) 3/8

~~~~~~~~~hok tốt~~~~~~~~~~~~

A/ \(\frac{1}{2}\)

B/ \(\frac{3}{8}\)  

\(\dfrac{3}{5}+\dfrac{6}{11}+\dfrac{7}{13}+\dfrac{2}{5}+\dfrac{16}{11}+\dfrac{19}{13}\\ =\left(\dfrac{3}{5}+\dfrac{2}{5}\right)+\left(\dfrac{6}{11}+\dfrac{16}{11}\right)+\left(\dfrac{7}{13}+\dfrac{19}{13}\right)\\ =\dfrac{5}{5}+\dfrac{22}{11}+\dfrac{26}{13}\\ =1+2+2\\ =5\)

5