SOLUTION: Each side of a square is 4 m long. When each side is increased by x m, the area is doubled. Find the value of x. Thank you!

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Each side of a square is 4 m long. When each side is increased by x m, the area is doubled. Find the value of x. Thank you!       Log On


   

Question 379518: Each side of a square is 4 m long. When each side is increased by x m, the area is doubled. Find the value of x. Thank you!
Answer by unlockmath(1688) About Me  (Show Source):
You can put this solution on YOUR website!
Hello,
We know the area is 14 Sq meters, right?
so we can set up this equation:
(x+4)^2=28
rewritten as:
x^2+8x+16=28
Let's complete the square. Subtract 16 to get:
x^2+8x=12
Add 16 to both sides:
x^2+8x+16=28
Factor:
(x+4)^2=28
Sq RT both sides:
x+4=+-sq rt 28
Subtract 4 to get:
x=-4+- sq rt 28
We get:
x=1.291 approx
We can check this out by adding 1.291 to 4 = 5.291
Square that and we get:
27.99 Approx or twice the area of the original.
Make sense?
RJ
www.math-unlock.com