\(X\)\(-\)\(\frac{30}{100}\)+\(\frac{20}{100}\)=\(20,2\)
\(X-\frac{1}{2}=20,2\)
\(X=20,2+\frac{1}{2}\)
\(X=\)\(10,6\)
CÂU B LÀM TƯƠNG TỰ BẠN TỰ LÀM NHA
\(x-\frac{30}{100}+\frac{20}{100}=20,2\) \(x\times\frac{40}{100}-\frac{40}{100}=4,4\)
\(x-\frac{3}{10}+\frac{2}{10}=\frac{202}{10}\) \(x\times\frac{4}{10}-\frac{4}{10}=\frac{44}{10}\)
\(x-\frac{3}{10}=\frac{202}{10}-\frac{2}{10}\) \(x\times\frac{4}{10}=\frac{44}{10}+\frac{4}{10}\)
\(x-\frac{3}{10}=\frac{200}{10}\) \(x\times\frac{4}{10}=\frac{48}{10}\)
\(x=\frac{200}{10}+\frac{3}{10}\) \(x=\frac{48}{10}:\frac{4}{10}\)
\(x=\frac{203}{10}\) \(x=\frac{12}{1}\)
\(x=20,3\) \(x=12\)
Chúc bạn học tốt !!!