将下列各数化简并表示成有理数的幂的形式

i) \( \left(\frac{2}{3}\right)^{3} \times\left(\frac{-6}{7}\right)^{2} \times\left(\frac{-7}{4}\right) \times \frac{3}{2} \)

ii) \( -\left(\frac{2}{5}\right)^{2} \times\left(\frac{5}{7}\right)^{2} \times \frac{49}{5}+\left(\frac{-4}{5}\right)^{3} \times \frac{5}{4} \times \frac{3}{4} \)


1)已知:  $\left(\frac{2}{3}\right)^{3} \times \ \left(\frac{-6}{7}\right)^{2} \times \ \frac{-7}{4} \times \ \frac{3}{2}$

求解: 我们需要求出 $\left(\frac{2}{3}\right)^{3} \times \ \left(\frac{-6}{7}\right)^{2} \times \ \frac{-7}{4} \times \ \frac{3}{2}$ 的值

解答: 

$\left(\frac{2}{3}\right)^{3} \times \ \left(\frac{-6}{7}\right)^{2} \times \ \frac{-7}{4} \times \ \frac{3}{2}$

$=\ \frac{2}{3} \ \times \ \frac{2}{3} \ \times \ \frac{2}{3} \ \times \ \frac{-6}{7} \ \times \frac{-6}{7} \ \times \frac{-7}{4} \ \times \frac{3}{2} \ $

$=\ \ \frac{-2}{7} \ \times \ \frac{2}{1} \ =\ \frac{-4}{7}$

2) 已知: $-\left(\frac{2}{5}\right)^{2} \times \ \left(\frac{5}{7}\right)^{2} \times \ \frac{49}{5} +\ \left(\frac{-4}{5}\right)^{3} \ \times \ \frac{5}{4} \ \times \ \frac{3}{4}$

求解: 我们需要求出 $-\left(\frac{2}{5}\right)^{2} \times \ \left(\frac{5}{7}\right)^{2} \times \ \frac{49}{5} +\ \left(\frac{-4}{5}\right)^{3} \ \times \ \frac{5}{4} \ \times \frac{3}{4}$ 的值

解答: $-\left(\frac{2}{5}\right)^{2} \times \ \left(\frac{5}{7}\right)^{2} \times \ \frac{49}{5} +\ \left(\frac{-4}{5}\right)^{3} \ \times \ \frac{5}{4} \ \times \frac{3}{4}$

 $=\ -\frac{4}{25} \ \times \ \frac{25}{49} \ \times \ \frac{49}{5} \ +\ \frac{-64}{125} \ \times \frac{5}{4} \ \times \frac{3}{4} \ $

$=\ \ \frac{-4}{5} \ +\ \frac{-12}{25} \ =\frac{-20}{25} \ +\ \frac{-12}{25} \ =\ \frac{-32}{25}$

更新于: 2022年10月10日

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