To solve for the variable "w" you only need to use algebra to get it alone on one side of the equals sign.
There would be 223 people every square mile
I am using the laws:
1)

2)

3)

an x is a base - the law is valid if the bases are the same number!
The solution in attachment :)
Well I solved it and This is what i got
We can simplify by 7
28/7 = 4
35/7 = 5
Answer- 4/5