Question

a rectangle has a length that is 5 inches greater than its width, and its area is 104 square inches. The equation(x+5) x=104 represents the situation, where x represents the width of the rectangle. (x+5) x=104 x2+5x-104=0. Determine the solutions of the equation. What solution makes sense for the situation?

Answer 1

x=8

Explanation:

Area of a rectangle=length×width

Area=104

Width=x

Length=5+x

104=x*(5+x)

104=5x+x^2

104-5x-x^2=0

x^2+5x-104=0

Can also be written as

-x^2-5x+104=0

Solve the quadratic equation using formula

−x2−5x+104=0

using the Quadratic Formula where

a = -1, b = -5, and c = 104

x=−b±√b2−4ac/2a

x=−(−5)±√(−5)2−4(−1)(104)/2(−1)

x=5±√25−(−416)/−2

x=5±√441/−2

The discriminant b^2−4ac>0

so, there are two real roots.

Simplify the Radical:

x=5±21/−2

x=-26/2 or 16/2

x=-13 or 8

The value of x can't be negative

So, x=8 is the answer