Lavander_tháng_Một
a) [math]\dfrac{3x^3-7x^2+5x+1}{2x^3-x^2-4x+3}=\dfrac{(x-1)^2(3x-1)}{(x-1)^2(2x+3)}=\dfrac{3x-1}{2x+3}[/math]b) [math]\dfrac{(x-y)^3-3xy(x+y)+y^3}{x-6y}=\dfrac{x^2(x-6y)}{x-6y}=x^2[/math]c) [math]\dfrac{x^2+y^2+z^2-2xy+2xz-2yz}{x^2-2xy+y^2-z^2}=\dfrac{(x-y+z)^2}{(x-y+z)(x-y-z)}=\dfrac{x-y+z}{x-y-z}[/math]