\(a,\frac{1}{2}x+\frac{3}{5}\left(x-2\right)=3\)
\(\Rightarrow\frac{1}{2}x+\frac{3}{5}x-\frac{6}{5}=3\)
\(\Rightarrow x\left(\frac{1}{2}+\frac{3}{5}\right)=3+\frac{6}{5}\)
\(\Rightarrow\frac{11}{10}x=\frac{21}{5}\)
\(\Rightarrow x=\frac{21}{5}:\frac{11}{10}\)
\(\Rightarrow x=\frac{42}{11}\)
\(b,\left(3\frac{1}{2}-x\right).1\frac{1}{4}=-1\frac{1}{20}\)
\(\Rightarrow\left(\frac{7}{2}-x\right)\cdot\frac{5}{4}=-\frac{21}{20}\)
\(\Rightarrow\frac{7}{2}-x=-\frac{21}{20}:\frac{5}{4}\)
\(\Rightarrow\frac{7}{2}-x=-\frac{21}{25}\)
\(\Rightarrow x=\frac{7}{2}--\frac{21}{25}\)
\(\Rightarrow x=\frac{7}{2}+\frac{21}{25}\)
\(\Rightarrow x=\frac{217}{50}\)
a) \(\frac{1}{2}.x+\frac{3}{5}.\left(x-2\right)=3\)
\(\frac{1}{2}.x+\frac{3}{5}.x-2=3\)
\(\frac{1}{2}.x+\frac{3}{5}.x=3+2\)
\(\frac{1}{2}.x+\frac{3}{5}.x=5\)
\(x.\left(\frac{1}{2}+\frac{3}{5}\right)=5\)
\(x.\frac{11}{10}=5\)
\(x=\frac{50}{11}\)
b) \(\left(3\frac{1}{2}-x\right).1\frac{1}{4}=-1\frac{1}{20}\)
\(\left(7-x\right).5=-21\)
\(\left(7-x\right)=-21:5\)
\(7-x=-4,2\)
\(x=7-\left(-4,2\right)\)
\(x=11,2\)
\(a,\frac{1}{2}x+\frac{3}{5}(x-2)=3\)
\(\frac{1}{2}x+\frac{3}{5}x-\frac{6}{5}=3\)
\(\left[\frac{1}{2}+\frac{3}{5}\right]x-\frac{6}{5}=3\)
\(\frac{11}{10}x-\frac{6}{5}=3\)
\(\frac{11}{10}x=\frac{21}{5}\Leftrightarrow x=\frac{42}{11}\)
Câu b tương tự
