A = \(\dfrac{18}{26}\) + (-\(\dfrac{5}{27}\)) + (-\(\dfrac{22}{86}\)) + \(\dfrac{12}{39}\) - \(\dfrac{32}{43}\)

A = \(\dfrac{9}{13}\) - \(\dfrac{5}{27}\) -  \(\dfrac{11}{43}\) + \(\dfrac{4}{13}\) - \(\dfrac{32}{43}\)

A = (\(\dfrac{9}{13}\) + \(\dfrac{4}{13}\)) - (\(\dfrac{11}{43}\) + \(\dfrac{32}{43}\)) - \(\dfrac{5}{27}\)

A = \(\dfrac{13}{13}\) - \(\dfrac{43}{43}\) - \(\dfrac{5}{27}\)

A = 1 - 1 - \(\dfrac{5}{27}\)

A = 0 - \(\dfrac{5}{27}\)

A = - \(\dfrac{5}{27}\)

B = -\(\dfrac{10}{12}\) + \(\dfrac{8}{15}\) - \(\dfrac{19}{56}\) + \(\dfrac{3}{-18}\) + \(\dfrac{28}{60}\)

B = - \(\dfrac{5}{6}\) + \(\dfrac{8}{15}\) - \(\dfrac{19}{56}\) - \(\dfrac{1}{6}\) + \(\dfrac{7}{15}\)

B = -(\(\dfrac{5}{6}\) + \(\dfrac{1}{6}\)) - \(\dfrac{19}{56}\) + (\(\dfrac{8}{15}\) + \(\dfrac{7}{15}\))

B = -1  - \(\dfrac{19}{56}\) + 1

B = - \(\dfrac{19}{56}\) 

`#lv`

`A=(-1)+(-5)+(-9)+...+(-101)`

`=-(1+5+9+...+101)`

Số số hạng là : 

`[101-(-1)]:4+1=26(` số hạng `)`

Tổng là : 

`[(-101)+(-1)]xx26:2=-1326`

Vậy `A=-1326`

__

`B=-5/17 . 8/19 + (-12)/17 . 8/19 - 11/19`

`=((-5)/17+(-12)/17).8/19-11/19`

`=-1.8/19-11/19`

`=-8/19-11/19`

`=-8/19+(-11)/19`

`=-19/19`

`=-1`

__

`C=10/1.6 + 10/6.11 + 10/11.16 + ... + 10/2016.2021`

`=2.(1-1/6+1/6-1/11+...+1/2016-1/2021)`

`=2(1-1/2021)`

`=2. (2021/2021-1/2021)`

`=2. 2020/2021`

`=4040/2021`

Gợi ý: Sử dụng tính chất phân phối của phép nhân đối với phép cộng để nhóm thừa số chung ra ngoài.

a) \(=\dfrac{157}{8}.\dfrac{12}{7}-\dfrac{61}{4}.\dfrac{12}{7}=\dfrac{12}{7}\left(\dfrac{157}{8}-\dfrac{61}{4}\right)=\dfrac{12}{7}.\dfrac{35}{8}=\dfrac{15}{2}\)

b) \(\dfrac{2}{5}.\dfrac{1}{3}-\dfrac{2}{15}\div\dfrac{1}{5}+\dfrac{3}{5}.\dfrac{1}{3}=\dfrac{1}{3}\left(\dfrac{2}{5}+\dfrac{3}{5}\right)-\dfrac{2}{15}.5=\dfrac{1}{3}.1-\dfrac{2}{3}=\dfrac{1}{3}-\dfrac{2}{3}=-\dfrac{1}{3}\)

c) \(=-\dfrac{80}{9}\)

d) \(=-\dfrac{1}{6}\)

a.=\(\dfrac{157}{8}:\dfrac{7}{12}-\dfrac{61}{4}:\dfrac{7}{12}=\dfrac{471}{14}-\dfrac{183}{7}=\dfrac{15}{2}\)

b.=\(\dfrac{2}{15}-\dfrac{2}{3}+\dfrac{1}{5}=-\dfrac{1}{3}\)

c.\(\left(\dfrac{10}{3}+2.5\right):\left(\dfrac{19}{6}-\dfrac{21}{5}\right)-\dfrac{11}{31}=\dfrac{35}{6}:\left(-\dfrac{31}{30}\right)-\dfrac{11}{31}=-\dfrac{175}{31}-\dfrac{11}{31}=-6\)

d.\(\left[6+\dfrac{1}{8}-\dfrac{1}{2}\right]:\dfrac{3}{12}=\dfrac{45}{8}:\dfrac{3}{12}=\dfrac{45}{2}\)

a, \(\dfrac{9}{18}-\dfrac{-7}{12}+\dfrac{13}{32}\)

\(=\dfrac{1}{2}+\dfrac{7}{12}+\dfrac{13}{32}\)

\(=\dfrac{13}{12}+\dfrac{13}{32}=\dfrac{143}{96}\)

b, \(\dfrac{5}{-8}+\dfrac{14}{39}-\dfrac{6}{10}\)

\(\dfrac{-5}{8}+\dfrac{14}{39}-\dfrac{3}{5}\)

\(=\dfrac{-5}{8}-\dfrac{3}{5}+\dfrac{14}{39}\)

\(=\dfrac{-49}{40}+\dfrac{14}{39}=\dfrac{-1351}{1560}\)

a) 9/18 - (-7/12) + 13/32

= 13/12 + 13/32

= 143/96

b) (5/-8) + 14/25 - 6/10

= (-13/200) - 6/10

= -133/200

Chúc bạn học tốt!! ^^

a: \(\dfrac{9}{18}-\dfrac{-7}{12}+\dfrac{13}{32}\)

\(=\dfrac{1}{2}+\dfrac{7}{12}+\dfrac{13}{32}\)

\(=\dfrac{48}{96}+\dfrac{56}{96}+\dfrac{39}{96}\)

\(=\dfrac{143}{96}\)

b: \(\dfrac{-5}{8}+\dfrac{14}{25}-\dfrac{6}{10}\)

\(=\dfrac{-125}{200}+\dfrac{112}{200}-\dfrac{120}{200}\)

\(=\dfrac{-133}{200}\)

a) \(\dfrac{20}{12}\)          b) \(\dfrac{15}{15}\)          c) \(\dfrac{24}{42}\)

d) \(\dfrac{26}{39}\)          e) \(\dfrac{0}{8}\)          g) \(\dfrac{15}{3}\)

a) \(\dfrac{15}{3}\)

b)\(\dfrac{15}{15}\)

c) \(\dfrac{24}{42}\)

d) \(\dfrac{26}{39}\)

e)\(\dfrac{0}{8}\)

f) \(\dfrac{15}{15}\)