If h(x) = 6 – x, what is the value of (h*h) (10)?

When you use the symbol * it is understood that the question is asking for the product of the function h(x) times h(x) evaluated at x = 10. Nevertheless, searching more context, I got the conclusion that this question refers to the composition of functions. In this case the right notation is (h o h) (10), which means h [h (x)] at x = 10. In this latter case: h [ h (10) ] = h [6 - 10] = h (- 4) = 6 - ( - 4) = 6 + 4 = 10. (h o h) (10) = 10.