\((\frac{9}{10}-\frac{2}{5})-\frac{1}{3}=\ \ \ \ \ | make\ a\ common\ denominator\\\\
(\frac{27}{30}-\frac{12}{30})-\frac{10}{30}=\ \ \ | omit\ the\ bracket\\\\\frac{27}{30}-\frac{12}{30}-\frac{10}{30}=\frac{27-12-10}{30}=\frac{5}{30}=\frac{1}{6}\\\ Solution\ is\ \frac{1}{6}.\)
