giúp em với mn ơi!
a) \(\Rightarrow\dfrac{4}{3}-x+\dfrac{1}{5}=\dfrac{1}{5}-\dfrac{1}{6}\)
\(\Rightarrow x=\dfrac{4}{3}+\dfrac{1}{6}=\dfrac{3}{2}\)
b) \(\Rightarrow3^x\left(1+3^2\right)=810\)
\(\Rightarrow3^x.10=810\Rightarrow3^x=81\Rightarrow x=4\)
c) \(\Rightarrow\left(2x+3\right)^2=25\)
\(\Rightarrow\left[{}\begin{matrix}2x+3=5\\2x+3=-5\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=1\\x=-4\end{matrix}\right.\)
\(\Leftrightarrow\)\(\dfrac{4}{3}-(x-\dfrac{1}{5})=\dfrac{1}{30}\)
\(\Leftrightarrow\)\((x-\dfrac{1}{5})=\dfrac{4}{3}-\dfrac{1}{30}\)
\(\Leftrightarrow\)\(x-\dfrac{1}{5}=\dfrac{13}{10}\)
\(x=\dfrac{3}{2}\)
mn ơi! giúp em câu này với em cần gấp lắm! em cảm ơn mọi người ạ=:>
