hi, i need to know sometheing guys

i have an equation here, which reads: x = 2/(y-3)^2 - 1

which then, according to the answer goes to: x = 2/y^2 - 6y + 8

can anyone tell me how the 6y and 8 in the second equation come about, because i don't understand where they come from??

thank you,

ryry