Given f(n)=n2−3nf(n) = n^2 - 3nf(n)=n2−3n and g(n)=n+4g(n) = n+4g(n)=n+4, find the expression for (f∘g)(n)(f \circ g)(n)(f∘g)(n).
n2+5n+4n^2 + 5n + 4n2+5n+4
n2−3n+4n^2 - 3n + 4n2−3n+4
n2+8n+16n^2 + 8n + 16n2+8n+16
n2−n−4n^2 - n - 4n2−n−4