What’s the closest ?

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

[10 points, algebra 2]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Someone answer this asap for the first five terms of a sequence are shown. 5, 11, 23, 47, 95, . . which recursive function defines the nth term in the sequence for n > 1? a. f(n) = f(n - 1) + 6 b) f(n) = f(n - 1) + 48 c) f(n) = 3 • f(n - 1) + 1 d) f(n) = 3 • f(n - 1) - 4