SOLUTION: In a room each wall is x feet. If you extend the room by 15 ft each way, the new area of the room is 900 ft. What was the original lengths of the walls?
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Question 1031094: In a room each wall is x feet. If you extend the room by 15 ft each way, the new area of the room is 900 ft. What was the original lengths of the walls? Found 2 solutions by rothauserc, LinnW:Answer by rothauserc(4718) (Show Source):
You can put this solution on YOUR website! (x + 15)^2 = 900
:
x^2 +30x + 225 = 900
:
x^2 +30x - 675 = 0
:
(x-15)*(x+45) = 0
:
x is 15 or -45
:
we reject the negative value
:
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original length of the walls was 15 feet
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You can put this solution on YOUR website! Set x = the original wall length
Each wall in the extended room is ( x + 15 )
So the area is ( x + 15 )( x + 15 )
( x + 15 )( x + 15 ) = 900
add -900 to each side
Factoring
(x + 45)(x - 15) = 0
So x = -45 or x = 15
We cannot have a negative length,
so the original length is 15
