SOLUTION: The area of a square can be tripled by increasing its length by 6 centimeters and increasing its width by 3 centimeters. What is the length of the side of the square?

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: The area of a square can be tripled by increasing its length by 6 centimeters and increasing its width by 3 centimeters. What is the length of the side of the square?      Log On


   

Question 1077768: The area of a square can be tripled by increasing its length by 6 centimeters and increasing its width by 3 centimeters. What is the length of the side of the square?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Original square is side x.

Area of original square, x%5E2.

The changed figure:
%28x%2B6%29%28x%2B3%29=3x%5E2


Finding x.
3x%5E2=x%5E2%2B9x%2B18
2x%5E2=9x%2B18
2x%5E2-9x-18=0
-
discrim, 81%2B4%2A2%2A18=225=15%5E2
-
x=%289%2B15%29%2F4
highlight%28x=6%29