A variable whose value is less than zero

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

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

The longer leg of a 30° 60° 90° triangle is 16 times square root of three how long is a shorter leg