<PRE><B>Question 573047</B>
If the sides of a square are lengthened by 6cm the area becomes 100cm^2. Find the length of a side of the original square.
(x+6)(x+6) = 100
FOIL
x^2 + 6x + 6x + 36 - 100 = 0
x^2 + 12x - 64 = 0
Factors to
(x+16)(x-4) = 0
The positive solution
x = 4
:
Check: (4+6) * (4+6) = 100
:
The length of a side of the original square is 4 cm.</PRE>