A rectangular plot is 30 feet long and 20 feet wide. The area will be doubled by adding a strip at one end and another strip of the same width on one side. What would be the width of the strip?

A = L*W = 30 * 20 = 600F^2.

Width = X feet.
A = (30+X) * (20+X) = 1200F^2,
600 + 30X + 20X + X^2 = 1200,
X^2 + 50X + 600 = 1200,
X^2 + 50X - 600 = 0,

(X-10)(X+60) = 0,
X - 10 = 0,
X = 10.

X+60 = 0,
X = - 60.

Select the + value of X:
X = 10 Feet.

To find the width of the strip, we need to determine the area of the initial rectangular plot and the area of the new plot after the strips are added.

The initial rectangular plot has a length of 30 feet and a width of 20 feet. Therefore, its area is given by multiplying the length and width: 30 feet * 20 feet = 600 square feet.

Since the area is doubled after the strips are added, the area of the new plot is 2 times the area of the initial plot: 2 * 600 square feet = 1200 square feet.

Let's assume the width of the strip is 'x' feet.

To find the dimensions of the new plot, we need to add the width of the strip to the length and to the width of the initial plot.

The length of the new plot will be 30 feet + x feet, and the width will be 20 feet + x feet.

The area of the new plot is given by multiplying the length and width:

(30 feet + x feet) * (20 feet + x feet) = 1200 square feet.

Expanding the equation:

(30x + (x)^2 + 600) = 1200.

Rearranging the equation:

(x^2 + 30x + 600) - 1200 = 0.

Now, we have a quadratic equation. To solve for 'x', we can use factoring, completing the square, or the quadratic formula.

If you solve the equation, you will find that the width of the strip is 10 feet.