\(\dfrac{-1}{13}\)

\(\dfrac{3}{5}\)

\(\dfrac{1}{6}\)

\(\dfrac{-270}{450}=\dfrac{-9}{15}\)
\(\dfrac{11}{-143}=\dfrac{1}{-13}\)
\(\dfrac{32}{12}=\dfrac{8}{3}\)
\(\dfrac{-26}{-156}=\dfrac{1}{6}\)

a)  − 270 450 = − 3 .90 5.90 = − 3 5

b)  11 − 143 = 11 − 13 .11 = 1 − 13

c)  − 26 − 156 = − 26 − 26 .6 = 1 6

a: \(\frac{-21}{28}=\frac{-21:7}{28:7}=\frac{-3}{4}\)

\(\frac{-39}{52}=\frac{-39:\text{13}}{52:13}=\frac{-3}{4}\)

\(\frac{-24}{63}=\frac{-24:3}{63:3}=\frac{-8}{21}\)

\(\frac{12}{-21}=\frac{12:3}{-21:3}=\frac{4}{-7}\)

b: \(\frac{-270}{450}=\frac{-270:90}{450:90}=\frac{-3}{5}\)

\(\frac{11}{-143}=\frac{-11}{143}=\frac{-11:\text{11}}{143:11}=\frac{-1}{13}\)

\(\frac{-132}{156}=\frac{-132:12}{156:12}=\frac{-11}{13}\)

\(\frac{-26}{169}=\frac{-26:13}{169:13}=\frac{-2}{13}\)

a)-270/450=-3/5

b)11/-143=-1/13

c)32/12=8/3

d)-26/-156=1/6

Bạn xem mình làm đúng chưa.

Bài 1: 

a: =-3/7

b: =-3/5

c: =1/13

d: =-1/2

Bài 2: 

a: \(=\dfrac{21\cdot11}{22\cdot9}=\dfrac{1}{2}\cdot\dfrac{7}{3}=\dfrac{7}{6}\)

b: \(=\dfrac{49\cdot8}{10}=\dfrac{196}{5}\)

xin lỗi tớ mới học lớp 5 thôi

*)\(\frac{-408}{-510}=\frac{408}{510}=\frac{4\cdot102}{5\cdot102}=\frac{4}{5}\)

*)\(\frac{-270}{450}=\frac{-27}{45}=\frac{\left(-3\right)\cdot9}{5\cdot9}=\frac{-3}{5}\)

- 26 - 156 = - 26 : ( - 26 ) - 156 : ( - 26 ) = 1 6