Problema Solution
If the sides of a square are lengthened by 6cm, the area becomes 196cm^2. Find the length of a side of the original square.
Answer provided by our tutors
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