Question

Given f(x)=3x+8 and g(x)=6x+6

then what is (f+g)(−1))

?

Answer 1

(f+g)(-1)
=f(-1)+g(-1), so;
f(x)=3x+8
f(-1)=3(-1)+8
f(-1)=-3+8
f(-1)=5

g(x)=6x+6
g(-1)=6(-1)+6
g(-1)=-6+6
g(-1)=0
Finally:
f(-1)+g(-1)
=5+0
=5. As a result, (f+g)(-1) is 5. Hope it help!