The speed of light in a vacuum is about 300,000,000 meters per second, which can be written a 3 x 10^n meters per second. what is n? '
a)-8
b)9
c)8
d)-9

Sophia wrote an equation to represent the revenue of a movie theater for one day. she let x represent the number of child tickets sold and y represents the nunver of adult tickets sold. if a child ticket cost $4, an adult ticket cost $6, and the total revenue for the daybwas $420, which equation could sophia use to represent the number of chikd and adult tickets that were sold?