Start with which equations are written in function notation?
The only ones are the first and last, not the “y=“ ones.
Then look at the equations.
h(x) = x^2 would be a parabola, so the range wouldn’t be all real numbers. It’d only be non-negative numbers.
g(x) = 1/2 x + 3/2 would be a line. This has a range of all real numbers.