Question

Помогите пожалуйста!!!!

Answer 1

$\frac{1}{9}c^{2}-\frac{16}{25}d^{2}=(\frac{1}{3}c)^{2}-(\frac{4}{5}d)^{2}=(\frac{1}{3}c-\frac{4}{5}d)(\frac{1}{3}c+\frac{4}{5}d)$