Given that [tex]$f(x)=x+3[tex]$[/tex] and [tex]$[/tex]g(x)=x^2-x[tex]$[/tex], find [tex]$[/tex](f+g)(-6)$[/tex], if it exists.
Select the correct choice below and, if necessary, fill in the answer box to complete your choice.
A. [tex]$(f+g)(-6) = \square$[/tex] (Simplify your answer.)
B. The value for [tex]$(f+g)(-6)$[/tex] does not exist.