Cho mik hỏi 2 câu này nx 8x³-12x²+6x-1=0 vs 3x³-6x²+9x=0 23/09/2021 Bởi Bella Cho mik hỏi 2 câu này nx 8x³-12x²+6x-1=0 vs 3x³-6x²+9x=0
$8x^3-12x^2+6x-1=0$ $\Rightarrow (2x-1)^3=0$ $\Rightarrow 2x-1=0$ $\Rightarrow x=\dfrac{1}{2}$ $3x^3-6x^2+9x=0$ $\Rightarrow3x(x^2-2x+3)=0$ $\Rightarrow 3x[(x-1)^2+2]=0$ Do $(x-1)^2+2>0$ $\forall x$ $\Rightarrow 3x=0$ $\Rightarrow x=0$ Bình luận
$8x^3-12x^2+6x-1=0$
$\Rightarrow (2x-1)^3=0$
$\Rightarrow 2x-1=0$
$\Rightarrow x=\dfrac{1}{2}$
$3x^3-6x^2+9x=0$
$\Rightarrow3x(x^2-2x+3)=0$
$\Rightarrow 3x[(x-1)^2+2]=0$
Do $(x-1)^2+2>0$ $\forall x$
$\Rightarrow 3x=0$
$\Rightarrow x=0$