Question

Ken has a rectangular shaped vegetable garden that is 15 feet by 9 feet. He would like to increase the length and width by the same amount, x, so the new garden is twice the current area. Find the value of x to the nearest tenth of a foot feet.

Answer 1

The current area is 15 x 9 = 135 square feet.

He wants to increase both the length and width by X:

Set up an equation:

(15 +x) * (9 +x) = 135 * 2

Simplify :

x^2 + 24x  +  135 = 270

Subtract 270 from both sides:

x^2 + 24x - 135 = 0

Use the quadratic formula to solve for x:

-24 +/- √(24^2 - 4(1*-135) / 2*1

x = 4.7 or -28.7

The answer has to be a positive value, so x = 4.7 feet.