a) \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
\(\Rightarrow0,75+0,25:x=0,4\)
\(\Rightarrow0,25:x=-0,35\)
\(\Rightarrow x=\dfrac{-5}{7}\)
b) \(\left|x-1\right|+3x=1\)
\(\Rightarrow\left|x-1\right|=1-3x\)
\(\Rightarrow\left[{}\begin{matrix}x-1=1-3x\\x-1=3x-1\end{matrix}\right.\)
Xét \(x-1=1-3x\)
\(\Rightarrow x+3x=1+1\)
\(\Rightarrow4x=2\)
\(\Rightarrow x=0,5\)
Xét \(x-1=3x-1\)
\(\Rightarrow x-3x=-1+1\)
\(\Rightarrow-2x=0\)
\(\Rightarrow x=0\)
ai đó giúp tôi trả lời nhanh nhanh câu này vs sắp đi hk rùi
a) \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
\(\Rightarrow\dfrac{1}{4}:x=\dfrac{2}{5}-\dfrac{3}{4}\)
\(\Rightarrow\dfrac{1}{4}:x=\dfrac{-7}{20}\)
\(\Rightarrow x=\dfrac{1}{4}:\dfrac{-7}{20}\)
\(\Rightarrow x=\dfrac{-5}{7}\)
a)\(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
\(\Rightarrow\dfrac{1}{4}:x=\dfrac{2}{5}-\dfrac{3}{4}\)
\(\Rightarrow\dfrac{1}{4}:x=\dfrac{-7}{20}\)
\(\Rightarrow x=\dfrac{1}{4}:\dfrac{-7}{20}\)
\(\Rightarrow x=\dfrac{-5}{7}\)