Question

tính m,n,p cho biết

a) \(\dfrac{1}{3}^m\)=\(\dfrac{1}{81}\) b)( \(\dfrac{3}{5}^n\) )=( \(\dfrac{9}{25})^5\) c) (-0,25)\(^p\)= \(\dfrac{1}{256}\)

(cho biết tính chất sau: vs a khác 0, a khác 1, nếu a\(^m\)=a\(^n\)thì m=n)

Answer 1

Tính chất bạn cho vẫn thiếu trong quá trình làm bài mình sẽ bổ sung!

a, \(\left(\dfrac{1}{3}\right)^m=\dfrac{1}{81}\)

\(\Rightarrow\left(\dfrac{1}{3}\right)^m=\left(\dfrac{1}{3}\right)^4\)

Vì \(\dfrac{1}{3}\ne\pm1;\dfrac{1}{3}\ne0\) nên \(m=4\)

b, \(\left(\dfrac{3}{5}\right)^n=\left(\dfrac{9}{25}\right)^5\)

\(\Rightarrow\left(\dfrac{3}{5}\right)^n=\left(\dfrac{3}{5}\right)^{10}\)

Vì \(\dfrac{3}{5}\ne\pm1;\dfrac{3}{5}\ne0\) nên \(n=10\)

c, \(\left(-0,25\right)^p=\dfrac{1}{256}\) \(\Rightarrow\left(-\dfrac{1}{4}\right)^p=\left(-\dfrac{1}{4}\right)^4\) Vì \(\dfrac{-1}{4}\ne\pm1;\dfrac{-1}{4}\ne0\) nên \(p=4\) Chúc bạn học tốt!!!

Answer 2

a)\(\left(\dfrac{1}{3}\right)^m=\dfrac{1}{81}\)

=>\(\left(\dfrac{1}{3}\right)^m=\left(\dfrac{1}{3}\right)^4\)

=>\(m=4\)

b)\(\left(\dfrac{3}{5}\right)^m=\left(\dfrac{9}{25}\right)^5\)

=>\(\left(\dfrac{3}{5}\right)^m=\left(\dfrac{3}{5}\right)^{10}\)

=>\(m=10\)

c)\(\left(-0,25\right)^p=\dfrac{1}{256}\)

=>\(\left(-0,25\right)^p=\left(\dfrac{1}{4}\right)^4\)

=>\(p=4\)