a) \(\frac{2}{3}\cdot\frac{1}{5}\cdot x=\frac{1}{3}\)
\(\frac{2}{15}\cdot x=\frac{1}{3}\)
\(x=\frac{1}{3}:\frac{2}{15}\)
\(x=\frac{5}{2}\)
b) \(\frac{3}{4}:3+\frac{1}{4}:3-\frac{1}{5}\)
=\(\left(\frac{3}{4}+\frac{1}{4}\right):3-\frac{1}{5}\)
=\(\frac{1}{3}-\frac{1}{5}\)
=\(\frac{2}{15}\)
Tk mk nha!!!