SOLUTION: Hello, I was wondering if you would be able to help me out on this problem. I'm not sure where to start: Use the given area to find the missing sides of the rectangle Are

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: Hello, I was wondering if you would be able to help me out on this problem. I'm not sure where to start: Use the given area to find the missing sides of the rectangle Are      Log On


   



Question 442586: Hello,
I was wondering if you would be able to help me out on this problem. I'm not sure where to start:
Use the given area to find the missing sides of the rectangle
Area = 42
Width = x
Length = 2x+8
The missing sides are_______.
Any help would be greatly appreciated. :)

Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
If you know the factors of 42, you can conclude that x = 3, because 3*(2*3 + 8) = 42. I would only try this if time was a major concern (e.g. during a competition, if it was my last 2 minutes of the SAT, etc.). However it's advised to show your work, as follows:

Given the area, width, and length, we can construct an equality:





This factors to

. The only positive solution is x = 3, so the dimensions are 3 and 14.