\(\dfrac{20}{41}+\dfrac{13}{21}+\dfrac{21}{41}+\dfrac{8}{21}\)

\(=\left(\dfrac{20}{41}+\dfrac{21}{41}\right)+\left(\dfrac{13}{21}+\dfrac{8}{21}\right)\)

\(=\dfrac{41}{41}+\dfrac{21}{21}\)

\(=\dfrac{1}{1}+\dfrac{1}{1}\)

\(=1+1\)

\(=2\)

\(\dfrac{5}{13}+\dfrac{-5}{17}+\dfrac{-20}{41}+\dfrac{8}{13}+\dfrac{-21}{41}\)

\(=\left(\dfrac{5}{13}+\dfrac{8}{13}\right)+\dfrac{-5}{17}+\left(\dfrac{-20}{41}-\dfrac{21}{41}\right)\)

\(=\dfrac{13}{13}+\dfrac{-5}{17}+\dfrac{-41}{41}\)

\(=1-\dfrac{5}{17}-1\)

\(=-\dfrac{5}{17}\)

khó nhìn quá e chỉnh lại đi nha

=5

\(\dfrac{\dfrac{36}{41}:\dfrac{9}{41}}{\dfrac{14}{21}:\dfrac{7}{21}}\) \(\times\) \(\dfrac{2}{5}\)

= \(\dfrac{\dfrac{36}{41}\times\dfrac{41}{9}}{\dfrac{14}{21}\times\dfrac{21}{7}}\) \(\times\) \(\dfrac{2}{5}\)

= \(\dfrac{4}{2}\) \(\times\) \(\dfrac{2}{5}\)

= \(\dfrac{4}{5}\)

Ta có: \(A=\dfrac{5}{13}+\dfrac{-5}{7}+\dfrac{-20}{41}+\dfrac{8}{13}+\dfrac{-21}{41}\)

\(=\left(\dfrac{5}{13}+\dfrac{8}{13}\right)+\left(\dfrac{-20}{41}+\dfrac{-21}{41}\right)+\dfrac{-5}{7}\)

\(=1-1+\dfrac{-5}{7}\)

\(=\dfrac{-5}{7}\)

Có 2 dấu = hả bạn

A.-9/2

b.-5/7

C.5/287

D.302/105

nêu cách tính nha bạn 

(-3/4+2/3):5/11+(-1/4+1/3):5/11

a)|x-13|-35-45=-47

b)(4+x).(x+3)=0

c)25-(5-x)=120-(28-5)

41:4=10 dư 1

27:2= 13 dư 1

65 : 3= 21 dư 2

41:6= 6 dư 5

21:5 = 4 dư 1

minh ko biet dat phep

tinh

chi tinh duoc thui

bn à

~~~~~~~~~~~~~

nhae

-207/221

đây chỉ là kết quả thôi cách làm mình sẽ đăng sau

bạn đăng nhanh lên nhé . mình đang cần lắm

\(\frac{5}{13}+-\frac{5}{17}+-\frac{20}{41}+\frac{8}{13}+-\frac{21}{41}\)

\(=\left(\frac{5}{13}+\frac{8}{13}\right)+\left(-\frac{20}{41}+-\frac{21}{41}\right)+-\frac{5}{17}\)

\(=1+\left(-1\right)+-\frac{5}{17}\)

\(=0+-\frac{5}{17}\)\(=-\frac{5}{17}\)

Ủng hộ tk Đúng nhé mọi người !!! ^^