How do u do this without a calculator

(2.3x10^12)divided(4.6x10^3)

If you have the following equation, 2/3x+5/6-x=2-3/4x what would you multiply each term by to get rid of all the fractions

What would the rule be for the reflection of y=-3

Acyclist bike x distance at 10 miles per hour .and returns over the same path at 8 miles per hour.what is the cyclist average rate for the round trip in miles per hour ?