Question

Hi.

Answer 1

1)

$\frac{d^2 - 9}{d^2 - 7d + 12} = \frac{(d - 3)(d + 3)}{(d - 3)(d - 4)} = \frac{d + 3}{d - 4}$

2)

$\frac{m^2 + 2mn + n^2}{m^2 - n^2} = \frac{(m + n)(m + n)}{(m - n)(m + n)} = \frac{m + n}{m - n}$

3)

$\frac{x^2 + xy - 6y^2}{x^2 - 3xy + 2y^2} = \frac{(x + 3y)(x - 2y)}{(x - y)(x - 2y)} = \frac{x + 3y}{x - y}$