J
jeratul


cho các số a,b,c,x,y,z thỏa mãn :
[TEX] \frac{x}{a+2b+c} = \frac{y}{2a+b-c} = \frac{z}{4a-4b+c} [/TEX]
c/m
[TEX] \frac{a}{x+2y+z} = \frac{b}{2x+y-z} = \frac{c}{4x-4y+z} [/TEX]
[TEX] \frac{x}{a+2b+c} = \frac{y}{2a+b-c} = \frac{z}{4a-4b+c} [/TEX]
c/m
[TEX] \frac{a}{x+2y+z} = \frac{b}{2x+y-z} = \frac{c}{4x-4y+z} [/TEX]