The area of a rectangular painting is given by the trinomial x2 + 4x – 21. What are the possible dimensions of the painting? Use factoring.

A. (x + 7) and (x + 3)
B. (x – 7) and (x + 3)
C. (x – 7) and ( x – 3)
D. (x + 7) and (x – 3)

1 answer

The trinomial can be factored as (x + 7)(x - 3) by finding factors of -21 that add up to 4. Therefore, the possible dimensions of the painting are x + 7 and x - 3. The answer is D.