Cách làm cho bạn:
a) x:$(\frac{−1}{3})^{3}=\frac{−1}{3}$ => x=$(\frac{−1}{3})^{4}=\frac{1}{81}$
b) x.$(\frac{−3}{7})^{5}=(\frac{−3}{7})^{7}$ => x=$(\frac{−3}{7})^{2}=\frac{9}{49}$
c) $(\frac{−2}{3})^{12}$:x=$(\frac{−2}{3})^{9}$ => x=$(\frac{−2}{3})^{12}:(\frac{−2}{3})^{9}=(\frac{−2}{3})^{3}$ nên x=$\frac{−8}{27}$
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