Question

помогите пожалуйста ​

Answer 1

$\frac{60}{a^{2} -9} - \frac{15a+25}{a^{2}-6a+9 } : \frac{3a^{2} + 5a}{2a^{2} - 18} = \frac{60}{a^{2}-9 } -\frac{5(3a+5)2(a^{2}-9) }{(a-3)^{2}a(3a+5) } =\frac{60}{a^{2}-9 } -\frac{10(a+3)}{a(a-3)} =\frac{60a-10(a+3)(a+3)}{a(a-3)(a+3)} =\frac{60a-10a^{2}-60a-90 }{a(a^{2}-9) } =-\frac{10(a^{2}-9) }{a(a^{2}-9) } =-\frac{10}{a}$