Please help!This is my last question, please help with all

QUESTION 1 Use the 2nd derivative test to find all relative extrema for the function f(x) = -2x3 + 3x2 + 72x. Relative maximum is at x = Relative minimum is at x = QUESTION 2 Find the absolute extrema for the function f(x) = 3x23 - 3x5/3 on the closed interval from 0 to 8. Round answers to the nearest thousandth (3 places after the decimal) if necessary. Absolute maximum is at X = Absolute minimum is at x = QUESTION 3 Find two nonnegative numbers x and y for which x + 3y = 30, such that x y is maximized. X = y =