Answer:
82.5 miles an hour
330 ÷ 4 = 82.5
Step-by-step explanation:
Try this solution (note, this is not the shortest way):
1. if the given length is 'l' and the width is 'w', then according to the condition 4*l=w;
2. according to the condition the perimeter is 30 ft. Formula of the perimeter is P=2(l+w), then 2(l+w)=30;
3. if to substitute '4*l' instead of 'w', the formula of the perimeter (from item no. 2) will be as 2(4*l+l)=30 or 10*l=30 ⇒ l=3 ft. The length is 3 ft.!
4. if l=3 ft., then w=4*3=12 ft. The width is 12 ft.!
5. Area is
A=w*l; A=12*3=<u>36 ft²</u>
Let's call the width of our rectangle 
and the length 
. We can say 
, since the length is equal to 4 cm greater than the width.
Also remember that the perimeter of a rectangle is the sum of two times the width and two times the length, or 
. To solve this problem, we can substitute in the information we know, as shown below:
Now, we can substitute in the width we found into the formula for length, which is :
The width of our rectangle is 
cm and the length of our rectangle is 
-15 is already rational itself, but it as a fraction:
-15/1
