Answer:
Step-by-step explanation:
Given the function f(x)=6+x
F(x) is dependent on x,
When x=1
f(x)=6+x
f(x)=6+1,
f(x)=7
When x=2
f(x)=6+x
f(x)=6+2
f(x)=8.
This will continue like this till we get to x=15
So when x=15
We will substitute x=15 into the function f(x)
f(x)=6+x
f(x)=6+15
f(x)=21
Then, the answer is 21.
