We will take length as variable l and width as variable w.
Formula for perimeter of the rectangle is P=2(l+w)
and l=w+2 and P≤30
First we replace l in formula for perimeter and get this inequality
2(w+2+w)≤30, than we divide this inequlity with 2 and get 2w+2≤15 =>
2w≤13 => w≤6.5
When we replace w in formula for l we get
l-2 ≤ 6.5 => l≤6.5+2 => l≤8.5
If you need some more explenation I am here
good luck!!!