Use distributive property to find and equal expression of 4 (6x+7y)

The serenity and the mystic are sail boats. the serenity and the mystic start at the same point and travel away from each other in opposite directions. the serenity travels at 16 mph and the mystic travels at 19 mph. how far apart will they be in 3 hours?

What is the simplified form of square root of 400 to the 100th power ?

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6