Question

sally is having a problem with her puppy leaving the yard so she decides to build a new fence. The length of the yard is 10 feet more than 3 timesthe width. She needs 60 feet of fencing to do the job. find the length of the yard

Answer 1

1. You have that the length of the yard is 10 feet more than 3 times the width. Then, you can write the following expression:

`l=3w+10`

Where
`l` is the length and
`w` is the width.

2. She needs 60 feet of fencing, which is the perimeter.

3. The formula of the perimeter of a rectangle is:

`P=2w+2l`

4. Therefore, you can substitute the first expression of the lenght into the formula of the perimeter and solve for the width:

`60=2w+2(3w+10)\\60=2w+6w+20\\40=8w\\w=5`

5. Now you can calculate the length:

`l=3(5)+10\\l=15+10\\l=25`

The answer is: The length of the yard is 25 feet.