Solve 9 through 20 or just solve one so you can give me an example

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

How many solutions does the nonlinear system of equations graphed below have? a. one b. zero c. four d. two

Acone is placed inside a cylinder. the cone has half the radius of the cylinder, but the height of each figure is the same. the cone is tilted at an angle so its peak touches the edge of the cylinder’s base. what is the volume of the space remaining in the cylinder after the cone is placed inside it?