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Exercise 944Algebra › Equations and radicalsL1Added 3 Nov 2026

A cubic with three roots

#cubic#factoring#roots

Statement

Solve in R\mathbb{R} the equation
x3−6x2+11x−6=0.x^3-6x^2+11x-6=0.

Hint

Test small integers.

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Solution

Test. x=1x=1: 1−6+11−6=01-6+11-6=0. Root. x=2x=2: 8−24+22−6=08-24+22-6=0. Root. x=3x=3: 27−54+33−6=027-54+33-6=0. Root.

Factor. x3−6x2+11x−6=(x−1)(x−2)(x−3)x^3-6x^2+11x-6=(x-1)(x-2)(x-3).

Conclusion. x∈{1,2,3}x\in\{1,2,3\}.