Question

Сократите дробь:

1) a^2 - 9 / a^2-4a+3;
2) x^2 - 7x + 12 / x^2 - 8x +15;

Answer 1

$frac{a^2 - 9}{a^2-4a+3}= frac{(a - 3)(a+3)}{(a-1)(a-3)}= frac{a+3}{a-1} \ frac{x^2 - 7x + 12}{x^2 - 8x +15}= frac{(x-3)(x-4)}{(x-3)(x-5)}= frac{x-4}{x-5}$