Answer 1

The Vector 2D class takes 3 arguments - self, x and y.
The __add__ magic method returns type of calculation after taking s aelf and other as argument.
First = Vector2D(5, 7)
Where 5 is self.x and 7 is self.y
Second = Vector2D(3, 9)
Where 3 is other.x and 9 is other.y

Result = first + second

Remember what __add__ returns (self.x + other.x, self.y + other.y)
print (result.x) prints out the x attributes i.e self.x + other.x and print (result.y) does the same thing.
I hope this helps