Will someone me understand? i don't know why i got the answer wrong.

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

Molly shared a spool of ribbon with 12 people. each person received 3 feet of ribbon. which equation can she use to find r, the number of feet of ribbon that her spool originally had?

Look at the figure below: triangle abc is a right triangle with angle abc equal to 90 degrees. the length of ac is 5 units and the length of ab is 4 units. d is a point above c. triangle adc is a right triangle with angle dac equal to 90 degrees and dc parallel to ab. what is the length, in units, of segment cd?