Respuesta :
By definition, a rectangle is a quadrilateral (4-sided polygon) with two sets of parallel and equal sides called length and width. The area of a rectangle is equal to the product of these two. The equation for the area is a quadratic equation. When you factor out a quadratic equation, it would be a product of two binomials such as (x-q)(x-r) = 0, where q and r are roots or zero's of the equation. You can find this by using the quadratic formula:
[tex]x= \frac{ -b+/- \sqrt{ b^{2}-4ac} }{2a} [/tex]
where a, b and c are the coefficients and constant of the quadratic equation with a general formula of ax²+bx+c=0. Substituting to the equation:
[tex]x= \frac{ -(-15)+/- \sqrt{ (-15)^{2}-4(1)(56)} }{2(1)} [/tex]
x = 7,8
Therefore, the binomials are (x-7) and (x-8). Since it was mentioned that the length is (x-7), then the width is (x-8).
[tex]x= \frac{ -b+/- \sqrt{ b^{2}-4ac} }{2a} [/tex]
where a, b and c are the coefficients and constant of the quadratic equation with a general formula of ax²+bx+c=0. Substituting to the equation:
[tex]x= \frac{ -(-15)+/- \sqrt{ (-15)^{2}-4(1)(56)} }{2(1)} [/tex]
x = 7,8
Therefore, the binomials are (x-7) and (x-8). Since it was mentioned that the length is (x-7), then the width is (x-8).
The expression that represents the width of the rectangle is x - 8
Area of a rectangle:
- area = lw
l = length
w = width
area = x² + 15x + 56
length = x - 7
Therefore,
x² - 15x + 56 = (x - 7) w
divide both sides by x - 7
w = x² - 15x + 56 / x - 7
w = (x - 7)(x - 8) / x - 7
w = x - 8
learn more on rectangle here: https://brainly.com/question/4529723