\[\boxed{\text{61.\ }\text{еуроки}\text{-}\text{ответы}\text{\ }\text{на}\text{\ }\text{пятёрку}}\]
Пояснение.
Решение.
\[\textbf{а)}\ при\ a = 10,25:\]
\[\frac{a^{2} - 43}{a - 6} + \frac{7}{a - 6} = \frac{a^{2} - 43 + 7}{a - 6} =\]
\[= a + 6 = 10,25 + 6 = 16,25.\]
\[\textbf{б)}\ при\ b = 3,5:\]
\[\frac{9b - 1}{b^{2} - 9} - \frac{6b - 10}{b^{2} - 9} =\]
\[= \frac{9b - 1 - 6b + 10}{b^{2} - 9} = \frac{3b + 9}{b^{2} - 9} =\]
\[= \frac{3}{3,5 - 3} = \frac{3}{0,5} = \frac{30}{5} = 6.\]