
Let's call the area of New York x and the area of California y.
x+y=204,192
y=108,530+x
Subtract x from each side of x+y=204,192.
y=204,192-x
Now, since both of the equations equal y, you can set the two equations equal to each other.
204,192-x=108,530+x
Add x to both sides.
204,192=108,530+2x
Subtract 108,530 from both sides.
95,662=2x
Divide both sides by 2.
47,831=x
Now, we can plug 47,831 into either of the equations for x to solve for y.
(47,831)+y=204,192
Subtract 47,831 from both sides.
y=156,361
The land area of California (y) is 156,361 square miles.
The land area of New York (x) is 47,831 square miles.
Hope this helps :)