Can someone please help with this I am confused about how to know which side is a and c

Colby and jaquan are growing bacteria in an experiment in a laboratory. colby starts with 50 bacteria in his culture and the number of bacteria doubles every 2 hours. jaquan starts with 80 of a different type of bacteria that doubles every 3 hours. let x equal number of days. colbys experiment follows the model: a.) y=50*2^x b.) y=50*2^8x c.) y=50*2^12x jaquans experiment follows the model: a.)80*2^x b.)80*2^8x c.)80*2^12x

Use the elimination method to solve the systems of equations. choose the correct ordered pair. 7x+4y=39

For the following equations, find the ratio of a to b. be sure to show all of your work. a. 3a = 6b b. 15a = 5b