Question

Упростите выражение

$(a- \frac{a}{b})*(a+ \frac{a}{b} )$

Answer 1

$(a - \frac{a}{b} )(a + \frac{a}{b}) = {a}^{2} - \frac{ {a}^{2} }{ {b}^{2} } = {a}^{2} - ( \frac{a}{b})^{2}$