x, y = y, x+y meaning?

Question

Could you explain the steps occuring?
Def f(n):
x = y = 1.0
for i in range (1,n):
x,y = y, x+y
return y/x
Print (f(3))

Answer 1

x, y = y, x+y
x is assigned y
y is assigned x+y

Answer 2

Sorry, mistype. Should be y/x