Question

The length of a rectangle is 3 more than twice the width. The area of the rectangle is 119 square inches. What are the dimensions of the rectangle?

If x = the width of the rectangle, which of the following equations is used in the process of solving this problem?

2x^ 2 + 3x - 119 = 0
3x ^2 + 3x - 119 = 0
6x ^2 - 119 = 0

Answer 1

The correct answer is 2x^ 2 + 3x - 119 = 0.

We can find this by starting with naming one of our unknowns as x. We can choose either, but for ease, we'll use the width.

Width = x

Now since the length is equal to twice the width plus 3, we can express the length as follows.

Length = 2x + 3

Now we also know that the area is equal to 119 and that length times width equals area. So we can use that equation and what we know to find our actual equation.

Length*Width = Area

(2x + 3)(x) = 119

2x^2 + 3x = 119

2x^2 + 3x - 119 = 0