C.
A doesn't work because x + x + x = 3x, not x^3.
B doesn't work because 14x + 10 - 2x has like terms, 14x and -2x can be combined, bit when you do so you get 14x - 2x, or 12x + 10. (So not 16x + 10)
D doesn't work because 12x^2 + 5x + 10 doesn't simplify; it can only be factored, and you cannot combine 12x^2 and 5x because their variables have different powers.
C, however, works fine. All they did is factor out a 3; if you distribute that 3 again, you get 12x + 16x back, so the two are equal.
Answer:
d 68
Step-by-step explanation:
do not know hope it maybe might help you sorry wish i could help
Alright, so it would be helpful to think about this question in terms of units. You're given a distance (meters) and speed (meters per second). You're asked for time (which is in seconds).
If you do

, your answer will be in seconds. So divide your distance (2.28 x 10^11 meters) by your speed (3.00 x 10^8 meters/second), and you should get your time!
So what you do it you multiply that number by 100 because it is out of 100% so therefore it would be 140.6%. But I cannot tell you that that is correct without more information.