When finding the value of x with the ration of the perimeters is 2 : 5 we have x as one polygon and 15 on the other polygon . what is x ?

So the perimiter are 2:5
x is one polygon and 15 is the other

so it is either 2:5=x:15 or 2:5=15:x

I would assume that it is 2:5=x:15 so
2 units=x and 5 units=15
5 units=15
dvide 5
1 unit=3
so 2 units=2 times 3=6

so the x=6

or

if 2:5=15:x then
2 units=15 and 5 units=x
2 units =15
divide 2
1 unit=7.5
5 units=5 times 7.5=37.5
so x=37.5

x could be 6 or 37.5 , depending on weather 2:5=x:15 or 2:5=15:x