can anyone teach me how to do this? i am already stuck on the 2nd part as this is highly confusing..different from what i get. matching the answers

http://img508.imageshack.us/img508/2271/optimizationl.jpg

When you isolate the y don't you just get

p= (x-1.8)(y-3.8) = 63.8611111111111.
y= (63.8611../(x-1.8)) + 3.8
How come there are soo many x in the options given.

please give some pointers. thank you