The last one is y=1,000x+150 please help

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 of the following is the explicit rule for a geometric sequence defined a recursive formula of a -5a for which the first term is 23?

I'm confused on this could anyone me and show me what i need to do to solve it.