Cho \(\frac{a}{b} = \frac{b}{c} = \frac{c}{d}\). Chứng minh rằng: \(\left(\frac{a+b+c}{b+c+d}\right)^3 = \frac{a}{d}\)

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Bài 4: Cho \(\frac{a}{b} = \frac{b}{c} = \frac{c}{d}\). Chứng minh rằng: \(\left(\frac{a+b+c}{b+c+d}\right)^3 = \frac{a}{d}\)