Can some1 help me with grade7s math?

Nell has a sales clerk job that pays $12 per hour for regular gas work hours. she gets double time for any hours over 40 that she works in a week. how many hours did nell work if her weekly pay was $744

What number should be added to the expression x^2+3x+ in order to create a perfect square trinomial? 3/2 3 9/4 9

List the sides of δrst in in ascending order (shortest to longest) if: m∠r =x+28°, m∠s = 2x+16°, and m∠t = x+12°