Which expression is equivalent to
(2g^3+4)^3
?
4g^6+16
4g^6 + 16g^3 +16
4g^6 + 8
4g^9 + 16g^3+8

Akayaker travels 3 miles upstream and 3 miles downstream in a total of 4 hours. in still water, the kayaker travels at a speed of 2 mph. what is the average speed of the river's current?