Question

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

Answer 1

Answer:

$(x+7)\text{ and } (x-3)$

Step-by-step explanation:

We have been given an expression $x^{2}+4x-21$ that represents area of a rectangular painting. We are asked to find the possible dimensions of the painting using factorization.

We will factor our quadratic expression by splitting the middle term.

$x^{2}+4x-21$

$x^{2}+7x-3x-21$

$x(x+7)-3(x+7)$

$(x+7)(x-3)$

Therefore, the possible dimensions of the painting are $(x+7)\text{ and } (x-3)$.

Answer 2

To find the dimensions you can just factor the equation...

x^2+4x-21

x^2-3x+7x-21

x(x-3)+7(x-3)

(x+7)(x-3) and this is equal to LW or WL

And note that x>3 for any possible solution.