Evaluate h(x)=x(x-8) for h(8), h(10), h(-3)+h(4), and h(4t). Help please!?

Question

I'm thinking I substitute the x(x-8) for each occurrence of "h" but am not sure how...?

Answer 1

h(8) means substitute 8 for each instance of x in h(x).

So:
h(x) = x(x-8)
h(8) = 8(8-8) = 8(0) = 0
h(10) = 10(10 - 8) = 10(2) = 20

etc.