I don’t know about 1 But number 2 is AB + xH2O = AB.xH2O
The correct method would be multiplying the speed of light by the time it takes to travel from the moon to Earth. This is because:
S=So+V*t
In which:
S= space
So= space at the start (origin)
V=speed or velocity
t=time
By multiplying miles/second by seconds you get miles as a result.
