\(\dfrac{-1}{4}x+\dfrac{2}{3}=\dfrac{5}{9}\)\(\Rightarrow\)\(\dfrac{-1}{4}x=\dfrac{5}{9}-\dfrac{2}{3}\)=\(\dfrac{-1}{9}\)
\(\Rightarrow\) x = \(\dfrac{-1}{9}:\dfrac{-1}{4}\)=\(\dfrac{4}{9}\).
\(x.\left(\dfrac{3}{5}\right)^3=\dfrac{3}{5}\)
\(\Rightarrow\)x=\(\dfrac{3}{5}:\left(\dfrac{3}{5}\right)^3=\left(\dfrac{3}{5}\right)^{-2}\)= \(2\dfrac{7}{9}\)
\(\left|x\right|\) + \(\dfrac{1}{5}=2-\left(\dfrac{2}{3}-\dfrac{3}{4}\right)\)=2 - \(\dfrac{-1}{12}\)=2\(\dfrac{1}{12}\)
\(\Rightarrow\)\(\left|x\right|\)=\(2\dfrac{1}{12}\)-\(\dfrac{1}{5}\)=\(1\dfrac{53}{60}\)
\(\Rightarrow\)x=\(\left[{}\begin{matrix}1\dfrac{53}{60}\\-1\dfrac{53}{60}\end{matrix}\right.\)
\(\left(\dfrac{-3}{4}\right)^x=\dfrac{81}{256}\)=\(\dfrac{(-3)^4}{4^4}\)=\(\left(\dfrac{-3}{4}\right)^4\)
\(\Rightarrow\) x = 4
14 Mẹo Vặt Sáng Tạo Dành Cho Học Sinh - YouTube
thử xem mẹo thứ 5 đi chứ theo mk đây là bài toán dễ lớp 6
1)\(-\dfrac{1}{4}x+\dfrac{2}{3}=\dfrac{5}{9}\)
\(-\dfrac{1}{4}x=\dfrac{5}{9}-\dfrac{2}{3}\)
\(-\dfrac{1}{4}x=-\dfrac{1}{9}\)
\(x=-\dfrac{1}{9}:\dfrac{-1}{4}\)
2) \(x\left(\dfrac{3}{5}\right)^3=\dfrac{3}{5}\)
\(x.\dfrac{27}{125}=\dfrac{3}{5}\)
\(x=\dfrac{3}{5}:\dfrac{27}{125}\)
\(x=2\dfrac{7}{9}=\dfrac{25}{9}\)
3) \(\left|x\right|+\dfrac{1}{5}=2-\left(\dfrac{2}{3}-\dfrac{3}{4}\right)\)
\(\left|x\right|+\dfrac{1}{5}=2-\dfrac{2}{3}+\dfrac{3}{4}\)
\(\left|x\right|+\dfrac{1}{5}=\dfrac{25}{12}\)
\(\left|x\right|=\dfrac{25}{12}-\dfrac{1}{5}\)
\(\left|x\right|=\dfrac{113}{60}\)
\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{113}{60}\\x=-\dfrac{113}{60}\end{matrix}\right.\)
4) \(\left(-\dfrac{3}{4}\right)^x=\dfrac{81}{256}\)
\(\left(-\dfrac{3}{4}\right)^x=\left(-\dfrac{3}{4}\right)^4\)
\(\Rightarrow x=4\)
