Đáp án:
Giải thích các bước giải:
`a) x^2-7x+6`
`= x^2 - 6x -x + 6`
`= (x^2 -6x) - (x-6)`
`= x(x -6 ) - (x-6)`
`= (x-1)(x-6)`
`b) x^2-9x+8`
`= x^2 - x - 8x + 8`
`= (x^2 -x) - (8x-8)`
`= x(x -1 ) - 8(x-1)`
`= (x-1)(x-8)`
`c) x ^3 − 7 x^ 2 + 5 x + 1`
`= x ^3 − x ^2 − 6 x^ 2 + 6 x − x + 1`
`= x^ 2 ( x − 1 ) − 6 x ( x − 1 ) − 1 ( x − 1 )`
`= ( x − 1 ) ( x ^2 − 6 x − 1 )`
`d) x^3-9x^2+3x+5`
`=x^3-x^2-8x^2+8x-5x+5`
`=x^2(x-1)-8x(x-1)-5(x-1)`
`=(x-1)(x^2-8x-5)`