Hi All,

I am teaching my self algebra using khan academy and Ive come across a problem I cant figure out. I am trying to solve composite functions and I cant figure out why a Plus sign is added to the equation, Could I be missing something that I am suppose to distrubute?

The functions is:

g(f(−1))=?

h(x)=4x+2

g(n)=n^3+2n^2−7n+5+f(n)

f(t)=3t−h(t)

f(−1)=−1

g(−1)=(−1)^3+2(−1)^2+(−7)(−1)+5+f(−1)

where does this............Δ Plus sign come from?