SOLUTION: if the sides of a square root are lenghtened by 6cm. The area becomes 196cm^2. Find the lenght of a side of the original square. what is the length of side square.

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Question 408244: if the sides of a square root are lenghtened by 6cm. The area becomes 196cm^2. Find the lenght of a side of the original square. what is the length of side square.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
I think you mean:
if the sides of a square are lengthened by 6 cm. The area becomes 196cm^2.
Find the length of a side of the original square.
what is the length of side square.
:
Let s = the side of the original square
:
Let (s+6) = side of the larger square
:
Area of the new square
(s+6)*(s+6) = 196
FOIL
s^2 + 12s + 36 = 196
s^2 + 12s + 36 - 196 = 0
A quadratic equation
s^2 + 12x - 160 = 0
Factors to
(s - 8)(s + 20) = 0
the positive solution is what we want here:
s = 8 cm, side of the original square
:
Then: 8 + 6 = 14 cm is the side of the larger square
Check this by finding the area: 14 * 14 = 196