a/ \(5,2x+7\frac{2}{5}=6\frac{3}{4}\)
\(\Rightarrow\frac{26}{5}x+\frac{37}{5}=\frac{27}{4}\)
\(\Rightarrow\frac{26}{5}x=\frac{27}{4}-\frac{37}{5}=\frac{135}{20}-\frac{148}{20}=\frac{13}{20}\)
\(\Rightarrow x=\frac{13}{20}:\frac{26}{5}=\frac{13}{20}.\frac{5}{26}=\frac{1}{8}\)
b/ \(2,4:\left(-\frac{1}{2}-x\right)=1\frac{3}{5}\)
\(\Rightarrow\left(-\frac{1}{2}-x\right)=2,4:1\frac{3}{5}=\frac{6}{5}:\frac{8}{5}=\frac{6}{5}.\frac{5}{8}=\frac{3}{4}\)
\(\Rightarrow x=-\frac{1}{2}-\frac{3}{4}=\left(-\frac{2}{4}\right)+\left(-\frac{3}{4}\right)=-\frac{5}{4}\)
a) \(5,2x+7\frac{2}{5}=6\frac{3}{4}\\ \Leftrightarrow\frac{26}{5}x+\frac{37}{5}=\frac{27}{4}\\ \Leftrightarrow\frac{26}{5}x=-\frac{13}{20}\Leftrightarrow x=-\frac{1}{8}\)
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