SOLUTION: You have a rectangle 20ft by 30ft and you want to double it in size? What is the new area? How much do you increase each side by showing the answer as a function of x?

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Question 449621: You have a rectangle 20ft by 30ft and you want to double it in size?
What is the new area? How much do you increase each side by showing the answer as a function of x?


Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
You have a rectangle 20ft by 30ft and you want to double it in size?
What is the new area?
How much do you increase each side by showing the answer as a function of x?
:
The new area: 2(20*30) = 1200 sq/ft
:
Let x = increase in length and width to double the area
:
The Area equation:
(x+20)*(x+30) = 1200
FOIL
x^2 + 30x + 20x + 600 = 1200
Combine like terms
x^2 + 50x + 600 - 1200 = 0
x^2 + 50x - 600 = 0
Factors
(x+60)(x-10) = 0
the positive solution is all we want here
x = 10 ft increase in the length and width
:
:
Check that: (10+20) * (10+30) = 1200