algebra · worked example

Solve x³ - 8 = (x - 2)(x^2 + 2x + 4)

Method: 立方差公式. Verified step-by-step solution with our free AI math solver.
Problem

x38x^3 - 8

Step-by-step solution

  1. 辨識為 立方差x38=x323x^3 - 8 = x^3 - 2^3

  2. 套用恆等式 a3b3=(ab)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2),其中 a=xa = xb=2b = 2

  3. 結果:(x2)(x2+2x+4)(x - 2)(x^2 + 2x + 4)

  4. 三項式因式 x2+2x+4x^2 + 2x + 4 的判別式為 416=12<04 - 16 = -12 < 0,因此在實數範圍內無法再進一步因式分解。

Answer

(x2)(x2+2x+4)(x - 2)(x^2 + 2x + 4)

Want to solve a different problem? Open the factoring solver →

Related worked examples