a) \(\frac{1}{4}+\frac{3}{4}x=\frac{3}{4}\Leftrightarrow\frac{3}{4}x=\frac{1}{2}\Leftrightarrow x=\frac{1}{2}\times\frac{4}{3}\Leftrightarrow x=\frac{2}{3}\)
b)\(1\frac{3}{4}x+1\frac{1}{2}=-\frac{4}{5}\Leftrightarrow\frac{7}{4}x+\frac{3}{2}=-\frac{4}{5}\Leftrightarrow\frac{7}{4}x=-\frac{23}{10}\)
\(\Leftrightarrow x=-\frac{23}{10}\times\frac{4}{7}\Leftrightarrow x=-\frac{46}{35}\)
c)\(\frac{3}{4}x+\frac{2}{5}x=1,2\Leftrightarrow x\left(\frac{3}{4}+\frac{2}{5}\right)=1,2\Leftrightarrow\frac{23}{20}x=1,2\)
\(\Leftrightarrow x=1,2\times\frac{20}{23}\Leftrightarrow x=\frac{24}{23}\)
d)\(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\Leftrightarrow\frac{1}{7x}=\frac{3}{14}-\frac{3}{7}\Leftrightarrow\frac{1}{7x}=-\frac{3}{14}\Leftrightarrow14=-3\times7x\)
\(\Leftrightarrow-21x=14\Leftrightarrow x=-\frac{2}{3}\)
e) \(-\frac{3}{4}-\left|\frac{4}{5}-x\right|=-1\Leftrightarrow\left|\frac{4}{5}-x\right|=-\frac{3}{4}+1\Leftrightarrow\left|\frac{4}{5}-x\right|=\frac{1}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}\frac{4}{5}-x=\frac{1}{4}\\\frac{4}{5}-x=-\frac{1}{4}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{11}{20}\\x=\frac{21}{20}\end{matrix}\right.\)
a, \(\frac{1}{4}+\frac{3}{4}x=\frac{3}{4}\\ \Rightarrow\frac{3}{4}x=\frac{1}{2}\\ \Rightarrow x=\frac{2}{3}\)
Vậy \(x=\frac{2}{3}\)
b, \(1\frac{3}{4}x+1\frac{1}{2}=\frac{-4}{5}\\ \frac{7}{4}x+\frac{3}{2}=\frac{-4}{5}\\ \Rightarrow\frac{7}{4}x=\frac{-23}{10}\\ \Rightarrow x=\frac{-46}{35}\)
Vậy \(x=\frac{-46}{35}\)
c, \(\frac{3}{4}x+\frac{2}{5}x=1,2\\ x\left(\frac{3}{4}+\frac{2}{5}\right)=\frac{6}{5}\\ x\cdot\frac{23}{20}=\frac{6}{5}\\ \Rightarrow x=\frac{24}{23}\)
Vậy \(x=\frac{24}{23}\)
d, \(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\\ \Rightarrow\frac{1}{7}:x=\frac{-3}{14}\\ \Rightarrow x=\frac{-2}{3}\)
Vậy \(x=\frac{-2}{3}\)
e, \(\frac{-3}{4}-\left|\frac{4}{5}-x\right|=-1\\ \Rightarrow\left|\frac{4}{5}-x\right|=\frac{1}{4}\\ \Rightarrow\left[{}\begin{matrix}\frac{4}{5}-x=\frac{1}{4}\\\frac{4}{5}-x=\frac{-1}{4}\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=\frac{11}{20}\\x=\frac{21}{20}\end{matrix}\right.\)
Vậy \(x\in\left\{\frac{11}{20};\frac{21}{20}\right\}\)
a) \(\frac{1}{4}+\frac{3}{4}x=\frac{3}{4}\)
\(\Leftrightarrow\frac{3}{4}x=\frac{3}{4}-\frac{1}{4}=\frac{1}{2}\)
\(\Leftrightarrow x=\frac{1}{2}:\frac{3}{4}\)
\(\Leftrightarrow x=\frac{2}{3}\)
Vậy : \(x=\frac{2}{3}\)
b) \(1\frac{3}{4}x+1\frac{1}{2}=-\frac{4}{5}\)
\(\Leftrightarrow\frac{7}{4}x=-\frac{4}{5}-\frac{3}{2}\)
\(\Leftrightarrow\frac{7}{4}x=-\frac{23}{10}\)
\(\Leftrightarrow x=-\frac{23}{10}:\frac{7}{4}\)
\(\Leftrightarrow x=-\frac{46}{35}\)
Vậy : \(x=-\frac{46}{35}\)
c) \(\frac{3}{4}x+\frac{2}{5}x=1,2\)
\(\Leftrightarrow\frac{23}{20}x=\frac{6}{5}\)
\(\Leftrightarrow x=\frac{6}{5}:\frac{23}{20}\)
\(\Leftrightarrow x=\frac{24}{23}\)
Vậy : \(x=\frac{24}{23}\)
d) \(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\)
\(\Leftrightarrow\frac{1}{7}:x=\frac{3}{14}-\frac{3}{7}=-\frac{3}{14}\)
\(\Leftrightarrow x=\frac{1}{7}:-\frac{3}{14}\)
\(\Leftrightarrow x=-\frac{2}{3}\)
Vậy : \(x=-\frac{2}{3}\)
e) \(-\frac{3}{4}-\left|\frac{4}{5}-x\right|=-1\)
\(\Leftrightarrow\left|\frac{4}{5}-x\right|=-\frac{3}{4}-\left(-1\right)\)
\(\Leftrightarrow\left|\frac{4}{5}-x\right|=\frac{1}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}\frac{4}{5}-x=\frac{1}{4}\\\frac{4}{5}-x=-\frac{1}{4}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{4}{5}-\frac{1}{4}\\x=\frac{4}{5}-\left(-\frac{1}{4}\right)\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{11}{20}\\x=\frac{21}{20}\end{matrix}\right.\)
Vậy : \(x\in\left\{\frac{11}{20},\frac{21}{20}\right\}\)
a,\(\frac{1}{4}+\frac{3}{4}x=\frac{3}{4}\)
\(\Leftrightarrow3x=2\)
\(\Leftrightarrow x=\frac{2}{3}\)
b,\(1\frac{3}{4}x+1\frac{1}{2}=\frac{-4}{5}\)
\(\Leftrightarrow\frac{7}{4}x+\frac{3}{2}=\frac{-4}{5}\)
\(\Leftrightarrow35x=-16-30\)
\(\Leftrightarrow x=-\frac{46}{35}\)
c,\(\frac{3}{4}x+\frac{2}{5}x=1,2\)
\(\Leftrightarrow\frac{3}{4}x+\frac{2}{5}x=\frac{6}{5}\)
\(\Leftrightarrow15x+8x=24\)
\(\Leftrightarrow23x=24\)
\(\Leftrightarrow x=\frac{24}{23}\)
d,\(\frac{3}{7}+\frac{1}{7}:x=\frac{3}{14}\)
\(\Leftrightarrow\frac{3}{7}+\frac{1}{7}x=\frac{3}{14};x\ne0\)
\(\Leftrightarrow\frac{3}{7}+\frac{1}{7x}=\frac{3}{14}\)
\(\Leftrightarrow\frac{1}{7x}=-\frac{3}{14}\)
\(\Leftrightarrow14=-21x\)
\(\Leftrightarrow x=-\frac{2}{3}\)
e,\(\frac{-3}{4}-|\frac{4}{5}-x|=-1\)
\(-|\frac{4}{5}-x|=-1+\frac{3}{4}\)
\(\Leftrightarrow-|\frac{4}{5}-x|=\frac{-1}{4}\)
\(\Leftrightarrow|\frac{4}{5}-x|=\frac{1}{4}\)
\(\Leftrightarrow\left[{}\begin{matrix}\frac{4}{5}-x=\frac{1}{4}\\\frac{4}{5}-x=-\frac{1}{4}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{11}{20}\\x=\frac{21}{20}\end{matrix}\right.\)
