Factor 3x^3-81

Problem

3*x3−81

Solution

1. Factor out the greatest common factor, which is 3

3*(x3−27)

2. Identify the expression inside the parentheses as a difference of cubes, since 27=3

3*(x3−3)

3. Apply the formula for the difference of cubes, a3−b3=(a−b)*(a2+a*b+b2) where a=x and b=3

3*(x−3)*(x2+3*x+3)

4. Simplify the constant term in the quadratic factor.

3*(x−3)*(x2+3*x+9)

Final Answer

3*x3−81=3*(x−3)*(x2+3*x+9)

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