To determine if a function is even, odd or neither, we need to verify by the definition of an odd and even function, as follows:
Even function:

Odd function:

In the number 9, we have the following function:

If we substitute the value from x to -x, we have the following:

but, by definition, we have:

From this, we can rewrite the function h(-x) as follows:

And from this, we can say that:

And from the solution developed above, we are able to conclude that the function described by h(x) in number 9 is an even function