Let $a$ be the smallest integer satisfying the inequality $x^2 - 15 < 2x$, and let $b$ be the largest integer satisfying the same inequality. What is $b-a$?
x2 - 15 < 2x ---> x2 - 2x - 15 < 0 ---> (x +3)(x - 5) < 0 ---> -3 < x < 5
The value of a is -2 and the value of b is 4 ---> b - a = 4 - -2 = 4 + 2 = 6