Step-by-step explanation:
The given function is :

(a) To find f(9), put x = 9 in the above expression.

(b) To find f(x+7), put x = x+7 in the above expression.

(c) To find f(-x), put x = -x in the above expression.

Hence, this is the required solution.
The answer is c i hope this help you out.
What exactly are you trying to figure out
Answer:
it's 0.7m, 77cm , 7m , 750 cm . hope I helped you .
The answer to your question is b