Question

[(x²-4x-21)÷(3x-9x)]÷[(3x-21)÷(x²-9)]=?

Answer 1

$\frac{ x^{2}-7 x+3x-21}{3x(x-3)} : \frac{3(x-7)}{(x-3)(x+3)} = \frac{(x-7)(x+3)}{3x(x-3)} * \frac{(x-3)(x+3)}{3(x-7)} = \frac{(x+3)^2}{9x}$

Answer 2

(x-7)(x+3)/3(x-3):3x(x-3):(x-3)(x+3)=(x-7)(x+3)(x-3)(x+3)/3(x-7)3x(x-3)=(x+3)²/9x