卡在這題?用 AI 解開它
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

x3−8x^3 - 8

Step-by-step solution

  1. 辨識為 立方差:x3−8=x3−23x^3 - 8 = x^3 - 2^3。

  2. 套用恆等式 a3−b3=(a−b)(a2+ab+b2)a^3 - b^3 = (a - b)(a^2 + ab + b^2),其中 a=xa = x、b=2b = 2。

  3. 結果:(x−2)(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 4−16=−12<04 - 16 = -12 < 0,因此在實數範圍內無法再進一步因式分解。

Answer

(x−2)(x2+2x+4)(x - 2)(x^2 + 2x + 4)

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

Related worked examples