Trong các dãy biến đổi dưới đây, dãy nào gồm toàn các phép biến đổi đúng?
\(\dfrac{x^2-4x+3}{-x^2-x+2}=\dfrac{\left(x-1\right)\left(x-3\right)}{\left(1-x\right)\left(x+2\right)}=\dfrac{\left(x-1\right)\left(x-3\right)}{-\left(x-1\right)\left(x+2\right)}=\dfrac{3-x}{x+2}\).\(\dfrac{x^2-4x+3}{-x^2-x+2}=\dfrac{\left(x-1\right)\left(x-3\right)}{\left(x-1\right)\left(x+2\right)}=\dfrac{x-3}{x+2}\).\(\dfrac{x^2-4x+3}{-x^2-x+2}=\dfrac{\left(x+3\right)\left(x+1\right)}{\left(x+2\right)\left(x+1\right)}=\dfrac{x+3}{x+2}\).\(\dfrac{x^2-4x+3}{-x^2-x+2}=-\dfrac{\left(2x-3\right)\left(x+1\right)}{\left(x+1\right)\left(x+2\right)}=\dfrac{3-2x}{x+1}\).