What is the first step when rewriting y = 3x2 + 9x – 18 in the form y = a(x – h)2 + k?

How do i do this? i don’t understand

Determine if the equation defines y as a function of x: 2xy = 1. yes o no

Identify all the cases where non-probability sampling is used when attempting to study the characteristics of a large city. studies on every subject in the population divide a population in groups and obtain a sample studies with a limited amount of time demonstrate existing traits in a population studies with the nth person selected