Question

[Lê Ngọc Bảo Trúc]

a) ^{\(\dfrac{\left(-3\right)^x}{81}\) = -27}

_b) [x-\(\dfrac{1^2}{2}\)] = 25

giúp dùm tớ với nha ❤❤❤

Answer 1

[Nguyễn Hoàng Minh]

\(a,\Rightarrow\dfrac{\left(-3\right)^x}{\left(-3\right)^4}=\left(-3\right)^3\\ \Rightarrow\left(-3\right)^{x-4}=\left(-3\right)^3\\ \Rightarrow x-4=3\Rightarrow x=7\\ b,Sửa:\left(x-\dfrac{1}{2}\right)^2=25\Rightarrow\left[{}\begin{matrix}x-\dfrac{1}{2}=5\\x-\dfrac{1}{2}=-5\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\dfrac{11}{5}\\x=-\dfrac{9}{5}\end{matrix}\right.\)