Answer:
A = 1
B = 2
C = 14
Step-by-step explanation:
Let's say f(x) = x. Then, f(x+h) = x + h. We can use that same rule in this question.
[tex]f(x)=x^2+14x+49\\\frac{f(x+h)-f(x)}{h}\\ \frac{[(x+h)^2+14(x+h)+49]-(x^2+14x+49)}{h}\\ \frac{x^2+hx+h^2+14x+14h+49-x^2+14x+49}{h}\\ \frac{(x^2-x^2)+2hx+h^2+(14x-14x)+14h+(49-49)}{h}\\ \frac{hx+2h^2+14h}{h}\\x+2h+14[/tex]
Therefore, A = 1, B = 2, C = 14
