SOLUTION: Dave and Jane wells have a new rectangular driveway. The perimeter of the driveway is 168 feet. the length is 12 feet longer than three times the width. what are the dimensions of

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Question 205647This question is from textbook intermediate algegra
: Dave and Jane wells have a new rectangular driveway. The perimeter of the driveway is 168 feet. the length is 12 feet longer than three times the width. what are the dimensions of the driveway. I followed an example in the book and not sure if it is understandable or not will post it anyway.
168=2w+2(2w+3) = 168=2w+4w+6 = 168=6w+6 168-6 = 6w +6-6=162/6 6w/6 w=27
2w+3=2(27) +3 = 54+3 = 57w=27 L=57
If you have the book I followed example 3 page 81. This question is from textbook intermediate algegra

Answer by Targetweek(62) About Me  (Show Source):
You can put this solution on YOUR website!
Yes, You have the right idea but you messed up in the beginning
1. First the perimiter equation
- 168=2L%2B2W
2. then set up an equation that states L in terms of W (in other words ex. L=2W) here is where you made your error
- L=3w%2B12
3. Now you have a systmes of equations
- 168=2L%2B2W
- L=3w%2B12
4. Substitute the 2nd equation into the 1st equation
- 168=2%283W%2B12%29%2B2W
5. Then solve for W
- 168+=+6W%2B24%2B2W
- 168+=+8W%2B24
- 168-24+=+8W%2B24-24
- 144+=+8W
- 144%2F8+=+8W%2F8
- 18=W
6. Now plug in the value for W into the 2nd equation
- L=3%2818%29%2B12
- L=54%2B12
- L=66
7. So the dimensions of the driveway are W = 18ft and L = 66ft
8. And finally plug them back in to check you numbers
- 168+=+2%2818%29%2B2%2866%29
- 168+=+36%2B132
- 168+=+168