Answer:
f(x)=-2x+9
f(4)+3=?
let x equal to 4
f(4)=-2(4)+8
f(4)=-8+9=+1
f(4)=1
then add 3 to f(4)
f(4)+3=1+3
f(4)+3=4
and he need f(4)+3 so the answer is
4
that's it