What’s y (solve and show work): 3(y-2)= -21

The administrator of a large assisted living facility wanted to know the average age of the residents living at the facility. he randomly selected 12 residents and determined their age, listed here: 80, 65, 75, 83, 68, 73, 88, 79, 94, 72, 79, 68 what's the average age of the sample of residents? a. 79 years old b. 68 years old c. 75 years old d. 77 years old

Could someone with number 1 and 2

Which coefficient matrix represents a system of linear equations that has a unique solution ? options in photo*