100,793 views
20 votes
20 votes
2. 3x3 - 4x2 + 9x - 12

User Bicycle
by
3.1k points

1 Answer

14 votes
14 votes

Polynomial Factoring

Factor the following polynomial:


p\mleft(x\mright)=3x^3-4x^2+9x-12

Let's group the first two and the last two terms:


p(x)=(3x^3-4x^2)+(9x-12)

Factoring out x^2 from the first two terms and 3 from the last two terms


p(x)=x^2(3x-4)+3(3x-4)

Note the expression 3x-4 is common to both groups. Factoring it out:


p(x)=\mleft(3x-4\mright)(x^2+3)

The second factor is a sum of squares, so it cannot be factored further. The final factorization is:


p(x)=\mleft(3x-4\mright)(x^2+3)

User Jeff Beck
by
3.3k points