easy question

Question

declare a var ，add 5 to it and print its value

x=4
x+=5
print（x）
someone who has corrected the question please tell me the right answer

Answer 1

From where is the question?
If the code you've provided is rejected, so try to do:

var = 4
var += 5
print(var)

... as in Python 'var' is not a reserved keyword, maybe the right expected answer need use a variable named 'var'?

Answer 2

I don't understand.
Are you asking what 4 + 5 is?
Or are you unsure what the += is.

If so, x += 5 is the same as writing:
x = x + (5)
Which is just 4 + 5.