Question

Cho ba phân số bằng nhau \(\dfrac{a}{b}=\dfrac{b}{c}=\dfrac{c}{d}\) . Chứng minh rằng : \(^{\left(\dfrac{a}{b}\right)^3}\)= \(\dfrac{a}{d}\)

Answer 1

Lời giải:
Vì $\frac{a}{b}=\frac{b}{c}=\frac{c}{d}$ nên:

$\left(\frac{a}{b}\right)^3=\frac{a}{b}.\frac{b}{c}.\frac{c}{d}$

Hay $\left(\frac{a}{b}\right)^3=\frac{a}{d}$

Ta có đpcm.

 

Answer 2

\(\left(\dfrac{a}{b}\right)^3=\dfrac{a}{b}\cdot\dfrac{a}{b}\cdot\dfrac{a}{b}=\dfrac{a}{b}\cdot\dfrac{b}{c}\cdot\dfrac{c}{d}=\dfrac{a}{d}\)