Please help, I'm so confused and never learned this in class, my teacher doesnt really TEACH us, he just assigns us work

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

Why do interests rates on loans to be lower in a weak economy than in a strong one

How to do this , and can some one explain