1C )
\(\frac{8^{15}.3^{16}}{4^{22}.9^8}\)
\(=\frac{\left(4.2\right)^{15}.\left(3^2\right)^8}{4^{22}.\left(3^2\right)^8}\)
\(=\frac{4^{15}.2^{15}.\left(1\right)^8}{4^{22}.\left(1\right)^8}\)
\(=\frac{2^{15}.\left(1\right)^8}{4^7.\left(1\right)^8}\)
\(=\frac{2^{15}.\left(1\right)^8}{\left(2^2\right)^7.\left(1\right)^8}\)
\(=\frac{2^{15}.\left(1\right)^8}{2^{14}.\left(1\right)^8}\)
\(=2\)
\(\left(1-2x\right)^2=9\)
Ta có :
\(\left(1-2x\right)^2=9\)
\(\Leftrightarrow\left(1-2x\right)^2=3^2\)
\(\Leftrightarrow\begin{cases}1-2x=3\\1-2x=-3\end{cases}\)
\(\Leftrightarrow\begin{cases}2x=1-3\\2x=1--3\end{cases}\)
\(\Leftrightarrow\begin{cases}2x=-2\\2x=4\end{cases}\)
\(\Leftrightarrow\begin{cases}x=-1\\x=2\end{cases}\)
Vậy \(x=\begin{cases}-1\\2\end{cases}\)
MK CÁM ƠN.
