If I want to do this:-1+2+4=7 how to write this in program?

Question

addition of number

Answer 1

in a script write:

sum = 1 + 2 + 4
print(sum)

Answer 2

in the interactive mode just enter 1 + 2 + 4, because you can use it as simple calculator.

Answer 3

x = 1
y = 2
z = 4
sum = x+y+z
print x+y+z
print (1+2+4)
print (sum)