How do you reflect -0.25x + 5 across the x-axis?

did you mean

y = -.25x + 5 ?

several ways to do this, here is a way that is simple to understand
Let's take two points on the line
x = 0, y = 5 ---> (0,5)
x = 4, y = 4 ---> (4,4)

when we reflect across the x-axis, the x values stays the same, but the way values becomes opposite
so (0,5) -----> (0,-5)
and (4,4) ----> (4,-4)

slope of new line = (-4+5)/(4-0) = 1/4
and since (0, -5) is the y-intercept
we have

y = (1/4)x - 5 or y = .25x - 5

sketch the above to see the situation.

If the function were h(x) = -0.25x + 5, could I multiply by -1 to get h(x) = 0.25 + 5? Or would this be -h(x) = 0.25 + 5?

To reflect a function across the x-axis, we need to change the sign of the y-coordinates. In this case, the function is -0.25x + 5.

To reflect -0.25x + 5 across the x-axis, we can use the following steps:

1. Replace the function with its opposite (-0.25x + 5 becomes +0.25x - 5).
2. Simplify the function if necessary. In this case, there is no need for simplification.
3. The resulting function, +0.25x - 5, is the reflection of -0.25x + 5 across the x-axis.

Therefore, the reflected function across the x-axis is +0.25x - 5.