Answer
(a) $\frac{25}{2}$
(b) $\frac{72}{49}$
Work Step by Step
(a) $\displaystyle \frac{30}{7}\div\frac{12}{35}=\frac{30*35}{7*12}=\frac{5*5}{1*2}=\frac{25}{2}$
(b) $\displaystyle \frac{30}{7}*\displaystyle \frac{12}{35}=\frac{30*12}{7*35}=\frac{6*12}{7*7}=\frac{72}{49}$
