how dose the variable x,y get defined as a,b without declaring it such as a=x b= y

Answer 1

I see the above code as declaration. This is because python unlike JavaScript for instance does not prepend var to declare variables.

In JavaScript:
var a = x
var b = y

In python:
a = x
b = y

The = operator is an assignment operator so python is smart to understand that, the item on the right should be a value to be put into the container of the item on the left, variable

Answer 2

Python is cool so you can also the following:

a,b = x,y

Answer 3

Using the Functions as Objects lesson. In that lesson x and y are variables of multiply (the function) when operation (the variable) is assigned to multiply (the function) operation = multiply then all atributes of multiply now apply to operation. Operation takes the variables of a and b already defined as 4, 7 and in the operation instance of multiply 4 and 7 now take the place of x and y.

Answer 4

thanks that makes sense

Answer 5

they cant