Antonia is factoring the polynomial, which has four terms.

21x3-63x2+15x-45

3[7x3-21x2+5x-15]

3[7x2 (x-3) + 5 (x-3) ]

Which is the complete factored form of her polynomial?

3 (x - 3) (7x^2 + 5).

Step-by-step explanation:

21x3 - 63x2 + 15x - 45

The greatest common factor of the constants is 3, so we have:

3 (7x^3 - 21x^2 + 5x - 15)

Now we factor this by grouping:

= 3 [7x^2 (x - 3) + 5 (x - 3)

= 3 (x - 3) (7x^2 + 5).

Step-by-step explanation:

It looks like the terms are:

(7x2 + 5) and (x - 3)