The product of sum and difference of $\frac{3}{5}$  and $\frac{4}{3}$  is

Sum of $\frac{3}{5}\text{and}\frac{4}{3}=\frac{3}{5}+\frac{4}{3}=\frac{9}{15}+\frac{20}{15}=\frac{29}{15}$

Difference of $\frac{3}{5}\text{and}\frac{4}{3}=\frac{4}{3}-\frac{3}{5}=\frac{20}{15}-\frac{9}{15}=\frac{11}{15}$

Product of $\frac{29}{15}$  and $\frac{11}{15}=\frac{29}{15}\times \frac{11}{15}=\frac{319}{225}$