Whats 8x^3-72? [^ mean to the power]

For how answer my question this will be the last question can you answer in math subject

Given a: b and b: c, find a: b: c. write the ratio in simplest form. a: b=6: 10 and b: c=21: 33

You are a male who just graduated from college with a bachelor's degree. you have a job paying $50,780.00/yr. a. how does your salary compare to the yearly median earnings for a male with a bachelor's degree? b. what is the difference between the yearly median earnings for a male with a bachelor's degree compared to a male who does not attend college after earning a high school diploma?