I am really confused on this question can some one help me out please

the length of a rectangular playing field is 5 ft less than twice its width If the perimeter of the playing field is 230 ft. find the length and width of the field.

I believe i am suppose to start with
P+2w+2L
I am lost after that please help

2L + 2W= P
but L+5= 2w
so
2L + L+5= P so figure what L is.

lets see if i am done this right
2L+L+5=230
3L+5=230
3L=-5+230
3L=225
3L/3=225/3
L=225/3
L=75

did I do this right

Then you must calculate W.
Then see if 2L + 2W = 230.