need help with this questions please provide explanation.

A marufacturer has determined that the total cost C of operating a factory is C - Q.5x 3 . 15x + 5000, where x is the number of units produced. At what level of production wil the average cost per unit be minimized? (The average cost per unit is C'x .) A rectangular page is to contain 36 square inches of print. The margins on each side are 1.5 inches Find the dimensions of the pago such that the least amount of papor is used. Analyzo and sketch a graph of the function! bach List tha following, if they unists critical numbers alent asymptote vertical asymptote x-intercept('s) y intercept interval's) where (() is increasing -2 0 interval's) where food is decreasing relative extroma points of infection intorva (o) whore fix) is concave upward interva 's) where fix] is concave downward plot the curve