Question

Сократите все три дроби:

Answer 1

а) $frac{a^2-9}{a+3} =frac{(a-3)(a+3)}{a+3}=a-3$
б) $frac{a^2-4ax+4x^2}{a^2-4x^2}=frac{a^2-2*a*2x+(2x)^2}{a^2-(2x)^2}=\ frac{(a-2x)^2}{(a-2x)(a+2x)}=frac{a-2x}{a+2x}$
в) $frac{c^2-81d^2}{(9d-c)^2}=frac{c^2-(9d)^2}{(c-9d)^2}=frac{(c-9d)(c+9d)}{(c-9d)^2}=frac{c+9d}{c-9d}$

Answer 2

$frac{ (alpha - 3)( alpha + 3)}{ alpha + 3} = alpha - 3$
$frac{( alpha - 2 x_)^{2} }{( alpha - 2 x_)( alpha + 2 x_)} = frac{ alpha - 2 x_}{ alpha + 2 x_}$
$frac{(c-9d) (c+9d) }{(c+9d)^{2} } = frac{(c-9d)}{(c+9d)}$