f(x)=square root of 5-x and g(x)=x^2+2x

a- find g(f(-1))
b-f(x)/g(x), state the domain, then evaluate for x=3

g(f) = f^2+2f

= √(5-x)^2 + 2√(5-x)
= (5-x) + 2√(5-x)
g(f(-1)) = (5+1)+2√(5+1) = 6+2√6

or, f(-1) = √(5+1) = √6
g(√6) = 6 + 2√6

domain of f is x<=5
domain of g is all reals

domain of f/g is all reals <=5, except x = -2 (where g=0)