[latex] \frac{a}{35a-25} / \frac{ a^{2} }{49a-70a+25} [/latex]  при [latex] a= \frac{5}{8} [/latex]

[latex] \frac{a}{35a-25} : \frac{ a^{2} }{49a-70a+25}= \frac{a}{5(7a-5)} \cdot \frac{ 25-21a }{a^2}= \frac{25-21a}{5a(7a-5)} =\frac{25-21\cdot 0.625}{5\cdot0.625(7\cdot0.625-5)} = \\\ =\frac{25-13.125}{3.125(4.325-5)}=-\frac{11.875}{3.125\cdot0.625}=-\frac{3.8}{0.625}=-\frac{3800}{625}=-6.08[/latex]