Please help me

A 72
B 143
C 333
D 36

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

The price of an item has been reduced by 30%. the original price was $30. what is the price of the item now ?

Complete the solution of the equation. find the value of y when x equals to 28 x+3y=28