Упростите выражение:
1) $\frac{c^2}{c - 9} - \frac{81}{c - 9}$;
2) $\frac{a^2}{(a - 6)^2} - \frac{36}{(a - 6)^2}$;
3) $\frac{3x + 5}{x^2 - 4} - \frac{2x + 7}{x^2 - 4}$;
4) $\frac{y^2}{y - 2} - \frac{4y - 4}{y - 2}$.
$\frac{c^2}{c - 9} - \frac{81}{c - 9} = \frac{c^2 - 81}{c - 9} = \frac{(c - 9)(c + 9)}{c - 9} = c + 9$
$\frac{a^2}{(a - 6)^2} - \frac{36}{(a - 6)^2} = \frac{a^2 - 36}{(a - 6)^2} = \frac{(a - 6)(a + 6)}{(a - 6)^2} = \frac{a^2 - 36}{(a - 6)^2} = \frac{a + 6}{a - 6}$
$\frac{3x + 5}{x^2 - 4} - \frac{2x + 7}{x^2 - 4} = \frac{3x + 5 - (2x + 7)}{x^2 - 4} = \frac{3x + 5 - 2x - 7}{x^2 - 4} = \frac{x - 2}{(x - 2)(x + 2)} = \frac{1}{x + 2}$
$\frac{y^2}{y - 2} - \frac{4y - 4}{y - 2} = \frac{y^2 - (4y - 4)}{y - 2} = \frac{y^2 - 4y + 4}{y - 2} = \frac{(y - 2)^2}{y - 2} = y - 2$
Пожауйста, оцените решение
