SOLUTION: The width of a rectangular room is 3 feet shorter than it is long. If the perimeter of the room is 42 feet, what is the width of the room? 1. 12 feer 2. 9 feet 3. 18 feet 4.

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Question 1142199: The width of a rectangular room is 3 feet shorter than it is long. If the perimeter of the room is 42 feet, what is the width of the room?
1. 12 feer
2. 9 feet
3. 18 feet
4. 6 feet
Found 2 solutions by Alan3354, ikleyn:
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
Same problem, different numbers.
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A rectangular room is 7 feet shorter than it is wide. If the perimeter of the room is 70 feet, what is the length of the room?
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L - W = 7
2L + 2W = 70

Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
.
The correct system of equations is


    L - W =  3      (1)

    L + W = 21      (2)     ( <<<---===  21 = 42/2 (!) )



Add equations (1) and (2), and you will get  2L = 3 + 21 = 24  ====>  L = 24/2 = 12.


Then from equation (2),  W = 21 - 12 = 9.



ANSWER.  The width of the room is 9 feet.