Ineed on the properties of exponents.

i know the process but combining numvers infront of the variables really confuse me ex. 2y squared times 3x. i dont know how to sinplify that

Aword processing program requires a 7- digit registration code made up of the digits 1,2,4,5,6,7 and 9 each number has to be used and no number can be used mor than once how many codes are possible