Range of a Variable

Question

Let x = (a+b)/2 and y = (a-b)/2

If it is given that,

-(infinity) < x < +(infinity) and

-(infinity) < y < +(infinity)



What's the range of a & b?

Answer 1

-inf < a < +inf

-inf < b < +inf

the range of a and b is any real number: (-infinity, +infinity)