Đáp án:
`(x-3)^4+(x-1)^4-16`
`=(x-3)^4+[(x-1)^2-4][(x-1)^2+4]`
`=(x-3)^4+(x^2-2x-3)(x^2-2x+5)`
`=(x-3)^4+(x-3x+x-3)(x^2-2x+5)`
`=(x-3)^4+(x-3)(x+1)(x^2-2x+5)`
`=(x-3)[(x-3)^3+(x+1)(x^2-2x+5)]`
`=(x-3)(x^3-9x^2+27x-27+x^3-2x^2+5x+x^2-2x+5)`
`=(x-3)(2x^3-10x^2+30x-22)`
`=2(x-3)(x^3-5x^2+15x-11)`
`=2(x-3)(x^3-x^2-4x^2+4x+11x-11)`
`=2(x-3)(x-1)(x^2-4x+11)`