Toán Phân tích đa thức này hộ em với x^4 -5x^2 +8x -12 15/09/2021 By Mary Phân tích đa thức này hộ em với x^4 -5x^2 +8x -12
$\text { Đáp án: }$ ` x⁴ – 5x² + 8x – 12 ` ` = x⁴ – 2x³ + 2x³ – 4x² – 4x² + 2x + 6x – 12 ` ` = x³(x – 2) + 2x²(x – 2) – x(x – 2) + 6(x – 2) ` ` = (x³ + 2x² – x + 6)(x – 2) ` ` = (x³ – x² + 3x² – 3x + 2x + 6)(x – 2) ` ` = {x²(x + 3) – x(x + 3) + 2(x + 3)}(x – 2) ` ` = (x² – x + 2)(x + 3)(x – 2) ` Trả lời
$x^4 -5x^2 +8x -12$ $=x^4 -2x^3 + 2x^3 – 4x^2 – x^2 + 2x + 6x -12$ $=x^3(x-2)+2x^2(x-2) – x (x-2) + 6(x-2)$ $=(x-2)(x^3+2x^2-x+6)$ $=(x-2)(x^3+3x^2-x^2-3x+2x+6)$ $=(x-2)[x^2.(x+3)-x(x+3)+2(x+3)]$ $=(x-2)(x+3)(x^2-x+2).$ Trả lời
$\text { Đáp án: }$
` x⁴ – 5x² + 8x – 12 `
` = x⁴ – 2x³ + 2x³ – 4x² – 4x² + 2x + 6x – 12 `
` = x³(x – 2) + 2x²(x – 2) – x(x – 2) + 6(x – 2) `
` = (x³ + 2x² – x + 6)(x – 2) `
` = (x³ – x² + 3x² – 3x + 2x + 6)(x – 2) `
` = {x²(x + 3) – x(x + 3) + 2(x + 3)}(x – 2) `
` = (x² – x + 2)(x + 3)(x – 2) `
$x^4 -5x^2 +8x -12$
$=x^4 -2x^3 + 2x^3 – 4x^2 – x^2 + 2x + 6x -12$
$=x^3(x-2)+2x^2(x-2) – x (x-2) + 6(x-2)$
$=(x-2)(x^3+2x^2-x+6)$
$=(x-2)(x^3+3x^2-x^2-3x+2x+6)$
$=(x-2)[x^2.(x+3)-x(x+3)+2(x+3)]$
$=(x-2)(x+3)(x^2-x+2).$