Question

Срочно ребятки 25б 1, пример номер-96

Answer 1

$\frac{a}{3a+3b} :\frac{a^{2} }{a^{2} -b^{2} } =\frac{a}{3(a+b)} *\frac{a^{2} -b^{2} }{a^{2} }=\frac{1}{3(a+b)}*\frac{(a -b)(a+b)}{a}=\frac{1}{3} *\frac{a-b}{a} =\frac{a-b}{3a}$