Growth and decay?? does anyone know i just got 5 questions..

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

Sam is a waiter at a local restaurant where he earns wages of $5 per hour sam figures that he also eams about $3 in tips for each person he serves sam works 6 hours on a particular day. if n represents the number of people sam serves that day, which of the following functions could sam use to figure ehis total earings for the do o a. en) = 30 o b. en) = 5n+ 18

Why is x= 4 a solution to the proportion 14/x 56/1 6