A basic perimeter equation= P=2L+2W
24=2W+2L
divide by 2 for each variable
so
12=2w+l
6=w+l
so, w+l could be 2+4, 3+3, or 1+5. now, if you input each of these into the equation
(2w)-3=l
so 2 could be 1,2,3,4, or 5.
2(1)-3=-1.... so it can't be w=1 l=5
2(2)-3=1... it can't be w=2 l=4
2(3)-3=3.... the length is 3.
So…your answer for the length is 3.