Question

[Trần Ngọc Hân]

viết số thích hợp vào chỗ chấm:

4/7= 8/...=.../21= 20/.....

Answer 1

[Hquynh]

\(\dfrac{4}{7}=\dfrac{8}{x}=\dfrac{y}{21}=\dfrac{20}{z}\\ =>\left\{{}\begin{matrix}x=\dfrac{7.8}{4}=14\\y=\dfrac{4.21}{7}=12\\z=\dfrac{7.20}{4}=35\end{matrix}\right.\\ =>\dfrac{4}{7}=\dfrac{8}{14}=\dfrac{12}{21}=\dfrac{20}{35}\)

Answer 2

[Sahara]

\(\dfrac{4}{7}=\dfrac{8}{x}=\dfrac{y}{21}=\dfrac{20}{z}\)
\(x=\dfrac{8\times7}{4}=14\)
\(y=\dfrac{8\times21}{14}=12\)
\(z=\dfrac{20\times21}{12}=35\)
Ta được dãy:
\(\dfrac{4}{7}=\dfrac{8}{14}=\dfrac{12}{21}=\dfrac{20}{35}\)