Question

A carpenter is making a rectangular form for a concrete pad she wants the length of the path to be 11 feet more than the width of the bed the area of the concrete pad must be 80 ft.² write the quadratic equation that will be used to find the dimensions of the pad

Answer 1

Answer:

Length = 16 or -5 feet.

Width = 5 or -16 feet.

Step-by-step explanation:

Let the length of the concrete pad = l

Let the width of the concrete pad = w

Given the following data;

Area of concrete pad, a = 80ft²

Translating the word problem into an algebraic equation, we have;

$l = 11 + w$

We know that, the area of rectangle, A = length * width

$A = l*w$

Substituting the values into the equation, we have;

$80 = (11 + w)w$

Expanding the bracket, we have;

$80 = 11w + w^{2}$

$w^{2} + 11w - 80 = 0$

*Solving the quadratic equation by using factorization method*

$w^{2} + 16w - 5w - 80 = 0$

$w(w + 16) - 5(w + 16) = 0$

$(w - 5)(w + 16) = 0$

Width, w = 5 feet or w = -16 feet.

Therefore, the width of the concrete pad is 5 feet or -16 feet.

To find its length, l;

$l = 11 + w$

When w = 5 feet

$l = 11 + 5$

Length, l = 16 feet

When w = - 16 feet

$l = 11 + (-16)$

$l = 11 - 16$

Length, l = -5 feet.

Hence, the dimensions of the concrete pad is 16 by 5 feet or -5 by -16 feet.