Question

сократите дробь:
а+3b/а^2-9b^2

Answer 1

$\displaystyle\bf\\\frac{a+3b}{a^{2}-9b^{2} } =\frac{a+3b}{a^{2} -(3b)^{2} } =\frac{a+3b}{(a+3b)(a-3b)} =\frac{1}{a-3b}$