28 less than twice a number is equal to the number. What is the number?

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Explain why the function is discontinuous at the given number a. (select all that apply.) f(x) = 1 x + 1 a = −1 f(−1) is undefined. lim x→−1+ f(x) and lim x→−1− f(x) exist, but are not equal. lim x→−1 f(x) does not exist. f(−1) and lim x→−1 f(x) exist, but are not equal. none of the above

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