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Question

ai  help me                                1/                $7^8.\left[-\frac{1}{7}\right]^8$

2/                \(\left[\frac{4}{3}\ri...

Hắc Hường · Accepted Answer

Giải:

1) $7^8.\left(-\dfrac{1}{7}\right)^8$

$=7^8.\left(\dfrac{1}{7}\right)^8$

$=7^8.\dfrac{1^8}{7^8}$

$=1$

2) $\left(\dfrac{4}{3}\right)^{10}.\left(-\dfrac{3}{4}\right)^{10}$

$=\left(\dfrac{4}{3}\right)^{10}.\left(\dfrac{3}{4}\right)^{10}$

$=\dfrac{4^{10}}{3^{10}}.\dfrac{3^{10}}{4^{10}}$

$=1$

3) $\left(-\dfrac{7}{2}\right)^{2006}.\left(-\dfrac{2}{7}\right)^{2006}$

$=\left(\dfrac{7}{2}\right)^{2006}.\left(\dfrac{2}{7}\right)^{2006}$

$=1$

4) $\left(-\dfrac{5}{13}\right)^{2007}.\left(\dfrac{13}{5}\right)^{2006}$

$=\left(\dfrac{5}{13}\right)^{2007}.\left(\dfrac{13}{5}\right)^{2006}$

$=\dfrac{5^{2007}.13^{2006}}{13^{2007}.5^{2006}}$

$=\dfrac{5}{13}$

Vậy ...Câu trả lời: Giải:

1) $7^8.\left(-\dfrac{1}{7}\right)^8$

$=7^8.\left(\dfrac{1}{7}\right)^8$

$=7^8.\dfrac{1^8}{7^8}$

$=1$

2) $\left(\dfrac{4}{3}\right)^{10}.\left(-\dfrac{3}{4}\right)^{10}$

$=\left(\dfrac{4}{3}\right)^{10}.\left(\dfrac{3}{4}\right)^{10}$

$=\dfrac{4^{10}}{3^{10}}.\dfrac{3^{10}}{4^{10}}$

$=1$

3) $\left(-\dfrac{7}{2}\right)^{2006}.\left(-\dfrac{2}{7}\right)^{2006}$

$=\left(\dfrac{7}{2}\right)^{2006}.\left(\dfrac{2}{7}\right)^{2006}$

$=1$

4) $\left(-\dfrac{5}{13}\right)^{2007}.\left(\dfrac{13}{5}\right)^{2006}$

$=\left(\dfrac{5}{13}\right)^{2007}.\left(\dfrac{13}{5}\right)^{2006}$

$=\dfrac{5^{2007}.13^{2006}}{13^{2007}.5^{2006}}$

$=\dfrac{5}{13}$

Vậy ...

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