Can someone me on # 4 and tell me if i set it up right? ?

What is the vertex form of f(x) = x2 + 6x + 3

Determine the number of outcomes in the event. decide whether the event is a simple event or not. upper a computer is used to select randomly a number between 1 and 9 comma inclusive. event upper b is selecting a number greater than 4. event upper b has nothing outcome(s). is the event a simple event? (yes or no) because event upper b has (fewer than, exactly, more than) one outcome.

What is the measure of ac? 5 units 13 units 26 units 39 units 3x- 2b 6x + 9