\(e.\dfrac{7}{10}\cdot\dfrac{-3}{5}+\dfrac{7}{10}\cdot\dfrac{-2}{5}-\dfrac{3}{10}\)

\(=\dfrac{7}{10}\cdot\left[\left(\dfrac{-3}{5}\right)+\left(\dfrac{-2}{5}\right)\right]-\dfrac{3}{10}\)

\(=\dfrac{7}{10}\cdot1-\dfrac{3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)

\(f.\dfrac{-3}{7}\cdot\dfrac{5}{9}+\dfrac{4}{9}\cdot\dfrac{-3}{7}+2\dfrac{3}{7}\)

\(=\dfrac{-3}{7}\cdot\left(\dfrac{5}{9}+\dfrac{4}{9}\right)+\dfrac{17}{3}\)

\(=\dfrac{-3}{7}\cdot1+\dfrac{17}{3}=\dfrac{-9}{21}+\dfrac{119}{21}=\dfrac{110}{21}\)

\(g.\dfrac{5}{9}\cdot\dfrac{10}{17}+\dfrac{5}{9}\cdot\dfrac{9}{17}-\dfrac{5}{9}\cdot\dfrac{2}{17}\)

\(=\dfrac{5}{9}\cdot\left(\dfrac{10}{17}+\dfrac{9}{17}-\dfrac{2}{17}\right)\)

\(=\dfrac{5}{9}\cdot1=\dfrac{5}{9}\)

\(a,\dfrac{3}{5}+\dfrac{-5}{9}=\dfrac{27-25}{45}=\dfrac{2}{49}.\)

\(c,\dfrac{-27}{23}+\dfrac{5}{21}+\dfrac{4}{23}+\dfrac{16}{21}+\dfrac{1}{2}=\dfrac{-23}{23}+\dfrac{21}{21}+\dfrac{1}{2}=-1+1+\dfrac{1}{2}=\dfrac{1}{2}.\)

\(d,\dfrac{-8}{9}+\dfrac{1}{9}.\dfrac{2}{9}+\dfrac{1}{9}.\dfrac{7}{9}=\dfrac{-8}{9}+\dfrac{1}{9}.\left(\dfrac{2}{9}+\dfrac{7}{9}\right)=\dfrac{-8}{9}+\dfrac{1}{9}.1=\dfrac{-8+1}{9}=\dfrac{-7}{9}.\)

a)A=\(\left(\dfrac{1}{3}-\dfrac{1}{3}\right)+\left(\dfrac{-3}{5}+\dfrac{3}{5}\right)+\left(\dfrac{5}{7}-\dfrac{5}{7}\right)+\left(\dfrac{-7}{9}+\dfrac{7}{9}\right)+\left(\dfrac{9}{11}-\dfrac{9}{11}\right)+\left(\dfrac{-11}{13}+\dfrac{11}{13}\right)+\dfrac{13}{15}\)

A=0+0+0+...+0+\(\dfrac{13}{15}\)

A=\(\dfrac{13}{15}\)

b) Ta có: \(-\dfrac{1}{9\cdot10}-\dfrac{1}{8\cdot9}-\dfrac{1}{7\cdot8}-...-\dfrac{1}{2\cdot3}-\dfrac{1}{1\cdot2}\)

\(=-\left(1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{4}-\dfrac{1}{4}+...+\dfrac{1}{9}-\dfrac{1}{10}\right)\)

\(=-\left(1-\dfrac{1}{10}\right)=\dfrac{-9}{10}\)

Chắc ko

nhìn thấy nản

Thấy mà hết muốn làm

-2/15

-4/35

-5/3

10

-8/3

-7/2

-9

-4/3

Chúc em học giỏi

\(=\dfrac{-2}{15}\\ =\dfrac{-4}{35}\\ =-1\\ =10\\ =\dfrac{-8}{3}\\ =-7\\ =-9\\ =\dfrac{-4}{3}\)

-2/15

-4/35

-5/3

10

-8/3

-7/2

-9

-4/3

a: \(\dfrac{3}{8}+\dfrac{7}{8}=\dfrac{3+7}{8}=\dfrac{10}{8}=\dfrac{5}{4}\)

b: \(\dfrac{7}{9}-\dfrac{4}{9}=\dfrac{7-4}{9}=\dfrac{3}{9}=\dfrac{1}{3}\)

c: \(\dfrac{5}{6}+\dfrac{1}{8}=\dfrac{20}{24}+\dfrac{3}{24}=\dfrac{20+3}{24}=\dfrac{23}{24}\)

d: \(\dfrac{9}{15}-\dfrac{2}{5}=\dfrac{3}{5}-\dfrac{2}{5}=\dfrac{3-2}{5}=\dfrac{1}{5}\)

e: \(\dfrac{2}{5}+\dfrac{3}{5}+\dfrac{9}{5}=\dfrac{2+3+9}{5}=\dfrac{14}{5}\)

g: \(\dfrac{8}{10}-\dfrac{1}{10}-\dfrac{3}{10}=\dfrac{8-1-3}{10}=\dfrac{4}{10}=\dfrac{2}{5}\)

h: \(\dfrac{23}{7}-\dfrac{4}{7}+\dfrac{2}{7}=\dfrac{23-4+2}{7}=\dfrac{21}{7}=3\)

a) \(\dfrac{-5}{9}+\dfrac{3}{5}-\dfrac{3}{9}+\dfrac{-2}{5}\)

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

=\(\dfrac{-8}{9}+\dfrac{1}{5}=-\dfrac{31}{45}\)

b) \(\dfrac{5}{17}-\dfrac{9}{15}-\dfrac{2}{17}+\dfrac{-2}{5}\)

=\(\left(\dfrac{5}{17}-\dfrac{2}{17}\right)-\left(\dfrac{9}{15}+\dfrac{2}{5}\right)\)

=\(\dfrac{3}{17}-1=\dfrac{-14}{17}\)

a) (-5/9) + 3/5 - 3/9 + (-2/5)

= (-5/9) - 3/9 + 3/5 + (-2/5)

= (-2/9) + 1/5

= -1/45

b) 5/17 - 9/15 - 2/17 + (-2/5)

= 5/17 - 2/17 - 9/15 + (-2/5)

= 3/17 - 1/5

= -2/85

Chúc bạn học tốt!! ^^

a: Ta có: \(-\dfrac{5}{9}+\dfrac{3}{5}-\dfrac{3}{9}+\dfrac{-2}{5}\)

\(=\dfrac{-8}{9}+\dfrac{1}{5}\)

\(=-\dfrac{31}{45}\)

b: Ta có: \(\dfrac{5}{17}-\dfrac{9}{15}-\dfrac{2}{17}+\dfrac{-2}{5}\)

\(=\dfrac{3}{17}-1\)

\(=-\dfrac{14}{17}\)

a) `1/3 - 1/4 : 2/5 = 1/3 - 5/8 = -7/24`

b) `6/7-(5/6+1/3)-(2/3+1/7) = 6/7-5/6-1/3-2/3-1/7`

`=(6/7-1/7)-(1/3+2/3)-5/6`

`=5/7-1-5/6`

`=-47/42`

c) `-5/9 . 2/5 + 4 5/9 + 5/9 . (-3/5)`

`= -5/9 . 2/5 + 4 + 5/9 + (-5/9) . 3/5`

`=-5/9 . (2/5 + 3/5-1) + 4`

`=-5/9 . 0 +4`

`=4`

d) 3 1/2 - (5 4/7 - 1 1/2) : 0,75`

`=7/2 - (39/7 - 3/2) : 3/4`

`= 7/2 - 57/14 : 3/4`

`=7/2 - 38/7`

`=-27/14`

De tke nma khonq bt lamm

Nguu

\(=\dfrac{85}{18}:\dfrac{85}{9}-\dfrac{136}{45}:\dfrac{136}{15}=\dfrac{1}{2}-\dfrac{1}{3}=\dfrac{1}{6}\)

Để tính tổng của biểu thức này, chúng ta cần thực hiện các phép cộng và trừ theo thứ tự từ trái sang phải.

\[4 + \frac{5}{6} - \frac{1}{9} \times \frac{1}{10} - \frac{7}{12} + \frac{1}{36} - 3 - \frac{1}{5} + \frac{1}{3} - \frac{1}{9} \times \frac{9}{5} + 1 - \frac{1}{3}\]

Đầu tiên, chúng ta sẽ làm các phép tính liên quan đến phân số:

\[= 4 + \frac{5}{6} - \frac{1}{90} - \frac{7}{12} + \frac{1}{36} - 3 - \frac{1}{5} + \frac{1}{3} - \frac{1}{5} + 1 - \frac{1}{3}\]

Tiếp theo, chúng ta sẽ tổng hợp các phân số:

\[= 4 + \frac{5}{6} - \frac{1}{90} - \frac{35}{90} + \frac{5}{180} - 3 - \frac{18}{90} + \frac{60}{180} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{1}{90} - \frac{35}{90} + \frac{5}{180} - 3 - \frac{2}{10} + \frac{10}{30} - \frac{2}{10} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{1}{90} - \frac{35}{90} + \frac{5}{180} - 3 - \frac{1}{5} + \frac{1}{3} - \frac{1}{5} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{36 + 35}{90} + \frac{5}{180} - 3 - \frac{1}{5} + \frac{2}{6} - \frac{1}{5} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - 3 - \frac{1}{5} + \frac{1}{3} - \frac{1}{5} + 1 - \frac{1}{3}\]

Tiếp theo, chúng ta sẽ tính tổng các số nguyên:

\[= 4 - 3 + 1\]

Cuối cùng, chúng ta sẽ tổng hợp các phân số:

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{1}{5} + \frac{1}{3} - \frac{1}{5} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{30}{90}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6} - \frac{71}{90} + \frac{5}{180} - \frac{18}{90} + \frac{30}{90} - \frac{18}{90} + 1 - \frac{1}{3}\]

\[= 4 + \frac{5}{6}

\(A=\left(\dfrac{1}{3}+\dfrac{3}{5}+\dfrac{1}{15}\right)-\left(\dfrac{3}{4}+\dfrac{2}{9}+\dfrac{1}{36}\right)+\dfrac{1}{64}\)

\(=\dfrac{5+9+1}{15}-\dfrac{27+8+1}{36}+\dfrac{1}{64}\)

=1/64