What is the volume? having trouble with this one. ​

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

Jose predicted that he would sell 48 umbrellas. he actually sold 72 umbrellas. what are the values of a and b in the table below? round to the nearest tenth if necessary

If the tip varies directly with the number of guest which equation represents between the tip,t, and the number of guest,g?