Which system of linear equations has the same solution as the one shown below? x - 4y= - 10 x + y = 5 1) 5x = 10 x + y = 5 2) -5y = -5 x+y=5 3)-3x = - 30 x + y = 5 4)-5y = -5 x - 4y = -10​

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