Найдите значение выражения: (2y-7)/(y^2-9)-(y-10)/(y^2-9) при y=3,1; y=-2.

\[\frac{2y - 7}{y^{2} - 9} - \frac{y - 10}{y^{2} - 9} =\]

\[= \frac{2y - 7 - y + 10}{y^{2} - 9} =\]

\[= \frac{y + 3}{(y + 3)(y - 3)} = \frac{1}{y - 3}\]

\[y = 3,1:\]

\[\frac{1}{y - 3} = \frac{1}{3,1 - 3} = \frac{1}{0,1} = 10.\]

\[y = - 2:\]

\[\frac{1}{y - 3} = \frac{1}{- 2 - 3} = \frac{1}{- 5} = - 0,2.\]