Phần tích đa thức sau thành nhân tử: x^3 -2016x^2+2015x
2 câu trả lời
Answer
`x^3 - 2016x^2 + 2015x`
`= x . (x^2 - 2016x + 2015)`
`= x . (x^2 - 2015x - x + 2015)`
`= x . [(x^2 - 2015x) - (x - 2015)]`
`= x . [x . (x - 2015) - (x - 2015) . 1]`
`= x . (x - 1) . (x - 2015)`
` x³ - 2016x² + 2015x `
` = x . ( x² - 2016x + 2015 ) `
` = x . ( x² - x - 2015x + 2015 ) `
` = x . [ ( x² - x ) - ( 2015x - 2015 ) ] `
` = x . [ x ( x - 1 ) - 2015 ( x - 1 ) ] `
` = x . [ ( x - 2015 ) . ( x - 1 ) ] `
` = x . ( x - 2015 ) ( x - 1 ) `