Question

Answer 1

Bài 2:

a) \(\Rightarrow5x=-100\Rightarrow x=-20\)

b) \(\Rightarrow\dfrac{-1}{4}x=-\dfrac{1}{9}\Rightarrow x=\dfrac{4}{9}\)

c) \(\Rightarrow\left|x+\dfrac{4}{5}\right|=\dfrac{9}{5}\)

\(\Rightarrow\left[{}\begin{matrix}x+\dfrac{4}{5}=\dfrac{9}{5}\\x+\dfrac{4}{5}=-\dfrac{9}{5}\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{13}{5}\end{matrix}\right.\)

d) \(\Rightarrow\left(-\dfrac{3}{4}\right)^x=\left(-\dfrac{3}{4}\right)^4\)\(\Rightarrow x=4\)

Bài 3:

\(2^{90}=\left(2^{10}\right)^9=1024^9\)

\(5^{36}=\left(5^4\right)^9=625^9\)

Do \(1024^9>625^9\)

\(\Rightarrow2^{90}>5^{36}\)