\(\dfrac{3x-2y}{4}=\dfrac{2z-4x}{3}=\dfrac{4y-3z}{2}\)
\(\Rightarrow\dfrac{4\left(3x-2y\right)}{16}=\dfrac{3\left(2z-4x\right)}{9}=\dfrac{2\left(4y-3z\right)}{4}\)
\(\Rightarrow\dfrac{12x-8y}{16}=\dfrac{6z-12x}{9}=\dfrac{8y-6z}{4}\)
Dựa vào tính chất dãy tỉ số bằng nhau ta có:
\(=\dfrac{12x-8y+6z-12x+8y-6z}{16+9+4}\)
\(=\dfrac{\left(12x-12x\right)+\left(8y-8y\right)+\left(6z-6z\right)}{29}=0\)
\(\Rightarrow\left\{{}\begin{matrix}12x=8y\Rightarrow\dfrac{x}{2}=\dfrac{y}{3}\\6z-12x=0\Rightarrow\dfrac{x}{2}=\dfrac{z}{4}\\8y=6z\Rightarrow\dfrac{y}{3}=\dfrac{z}{4}\end{matrix}\right.\)
\(\Rightarrow\dfrac{x}{2}=\dfrac{y}{3}=\dfrac{z}{4}\)
(3x-2y)/4 = (2z-4x)/3 = (4y-3z)/2 =
= (12x-8y)/16 = (6z-12x)/9 = (8y-6z)/4 = (12x-8y + 6z-12x + 8y-6z)/(16+9+4) = 0
<=>
{12x - 8y = 0
{6z - 12x = 0
{8y - 6z = 0
<=>
{x/2 = y/3
{z/4 = x/2
{y/3 = z/4
<=> x/2 = y/3 = z/4
Học tốt!
