Question 846807
One side of a square is increased by 7 𝑓𝑡 and the other side of the square is decrease by 10 𝑓𝑡.
 The area of the new figure is 110 𝑓𝑡2.
 Find the length of a side of the original square
:
Let x = the side of the original square
:
New area equation
(x+7)*(x-10) = 110
FOIL
x^2 - 10x + 7x - 70 = 110
x^2 - 3x - 70 - 110 = 0
x^2 - 3x - 180 = 0; our old friend, the quadratic equation!
Factors to
(x-15)((x+12) = 0
the positive solution is all we want here
x = 15 ft is the side of square
:
:
Check this: 22 * 5 = 110