evaluate the function for f(x)=x^2+8 and g(x)=x-9
1.) (fg)(-5)

2.) (f-g)(-8)

help I can't get the right answer

Your notation here is a bit confusing. For the first question, is that supposed to be f(-5)*g(-5), or is it f(g(-5))?

If the latter, then what you do is first find the value of g(-5), then shove that value as x into f(x).

I've not seen the notation (f-g)(-5) before - perhaps it means f(-5) - g(-5)? If so, then it's pretty straight forward.