Question 253526
You are close but the perimeter of a rectangle is all the sides added together so you would have length + length + width + width = 30

you can use L for length and w for width

So the two equations you will have are:

L = 2W
L+L+W+W=30 or 2L + 2W = 30

use substitution:

2(2W) + 2W = 30
4W + 2W = 30
6W = 30  divide both sides by 6
W = 5

Sub back into L=2(w)  so L = 2(5)  
L = 10

Hope this helps