Để tuyển nhân viên, một công ty tổ chức kiểm tra 3 vòng độc lập

Me because some of question i don’t understand

Which value is not a solution of 8x^3 – 1 = 0

Solve with work both bert and ernie received an increase in their weekly salaries. bert's salary increased from $520 to $520. ernie's salary went from $580 to $645. find the percent of increase for each salary. what was the larger of the two percents ?