\(3\cdot81=9\cdot27\)

\(243\cdot3=9\cdot81\)

a: \(\left(-3\right)\cdot\left(-24\right)=6\cdot12\)

\(\Leftrightarrow\dfrac{-3}{6}=\dfrac{12}{-24};\dfrac{-3}{12}=\dfrac{6}{-24};\dfrac{6}{-3}=\dfrac{-24}{12};\dfrac{12}{-3}=\dfrac{-24}{6}\)

b: \(12\cdot0.9=18\cdot0.6\)

\(\Leftrightarrow\dfrac{12}{18}=\dfrac{0.6}{0.9};\dfrac{12}{0.6}=\dfrac{18}{0.9};\dfrac{18}{12}=\dfrac{0.9}{0.6};\dfrac{0.6}{12}=\dfrac{0.9}{18}\)

ối dồi ôi em chưa lớp 7 đâu

c: \(1.05\cdot42=30\cdot1.47\)

nên \(\dfrac{1.05}{1.47}=\dfrac{30}{42};\dfrac{1.05}{30}=\dfrac{1.47}{42};\dfrac{1.47}{1.05}=\dfrac{42}{30};\dfrac{30}{1.05}=\dfrac{42}{1.47}\)

d: \(3\cdot81=27\cdot9\)

nên \(\dfrac{3}{27}=\dfrac{9}{81};\dfrac{3}{9}=\dfrac{27}{81};\dfrac{27}{3}=\dfrac{81}{9};\dfrac{9}{3}=\dfrac{81}{27}\)

1/ \(\frac{5}{-9}=\frac{15}{-27}\)

2/ \(\frac{-27}{-9}=\frac{15}{5}\)

3/ \(\frac{5}{15}=\frac{-9}{-27}\)

4/ \(\frac{-9}{5}=\frac{-27}{15}\)

tíc mình nha

5/(-9)=15/(-27)

5/15=-9/(-27)

-27/(-9)=15/5

-27/15=(-9)/5

\(\dfrac{27}{3}=\dfrac{243}{27}=\dfrac{81}{9}\)

\(\dfrac{9}{3}=\dfrac{81}{27}=\dfrac{243}{81}\)

Ta có đăng thức :

3.81 = 9 . 27

=> ta lập đc các TL thứ là :

\(\dfrac{3}{9}=\dfrac{27}{81};\dfrac{3}{27}=\dfrac{9}{81};\dfrac{81}{9}=\dfrac{27}{3};\dfrac{81}{27}=\dfrac{9}{3}\)

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