`#tnvt`
`A=x^3-3x^2+4`
`=x^3+x^2-4x^2+4`
`=x^2(x+1)-4(x^2-1)`
`=x^2(x+1)-4(x-1)(x+1)`
`=(x+1)(x^2-4x+4)`
`=(x+1)(x-2)^2`
`B=x^2+y^2-x^2y^2+xy-x-y`
`=xy^2+y^2-y-x-x^2y^2-xy^2+xy+x^2`
`=(xy^2+y^2-y-x)-x(xy^2+y^2-y-x)`
`=(1-x)(xy^2+y^2-y-x)`
`=(1-x)(xy^2+y^2+xy-xy-y-x)`
`=(1-x)[y(xy+y+x)-(xy+y+x)]`
`=(1-x)(y-1)(xy+y+x)`
`a)x(x-11)-x+11=0`
`<=>x(x-11)-(x-11)=0`
`<=>(x-11)(x-1)=0`
`<=>[(x=11),(x=1):}`
Vậy `x\in{11;1}`
`b)5x^3=10x`
`<=>5x^3-10x=0`
`<=>5x(x^2-2)=0`
`<=>[(5x=0),(x^2-2=0):}`
`<=>[(x=0),(x^2=2):}`
`<=>[(x=0),(x=+-\sqrt{2}):}`
Vậy `x\in{0;+-\sqrt{2}}`
