SOLUTION: Hello I have tried to figure out this problem for like two or three days and it just doesn't make since to me so if you could be so kind as to help me figure it out, I would be gre

Algebra ->  Rectangles -> SOLUTION: Hello I have tried to figure out this problem for like two or three days and it just doesn't make since to me so if you could be so kind as to help me figure it out, I would be gre      Log On


   

Question 189234: Hello I have tried to figure out this problem for like two or three days and it just doesn't make since to me so if you could be so kind as to help me figure it out, I would be greatly appriciated. The question or the problem is:
The length of a rectangle is 1 less than three times it's width. The perimeter is 30 ft. Find the length of this rectangle.
You might not be able to figure it out either but if you can't I appriciate the offer anyways. Thank you so much for your help.
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Let L=length and W=width

Since "The length of a rectangle is 1 less than three times it's width", this means that L=3W-1 and because "The perimeter is 30 ft", this tells us that P=30


P=2L%2B2W Start with the perimeter formula


30=2%283W-1%29%2B2W Plug in P=30 and L=3W-1


30=6W-2%2B2W Distribute


30%2B2=6W%2B2W Add 2 to both sides.


32=8W Combine like terms.


32%2F8=W Divide both sides by 8 to isolate W.


4=W Reduce.


W=4 Rearrange the equation.

So the width is 4 feet.


L=3W-1 Go back to the first equation


L=3%284%29-1 Plug in W=4


L=12-1 Multiply.


L=11 Subtract.


So the length is 11 feet.