X^2-1/(2x-1)-(x-2) algebric fraction

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

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Select a graph that have an equation with a < 0