ANSWER
b > 1
Step-by-step explanation
Suppose that a < -1.
We need to find the value of b such that:
a * b < a
This means that:
a * b < -1
For this to be possible, b must first be a positive number. Because if b is negative, then:
a * b > 0
Which would mean that a * b is greater than a.
For b to be a positive number that satisfies the inequality, then b cannot be less than 1. This is because if b is less than 1, then:
a * b > a
Therefore, b must be a positive number that is greater than 1.
This means that:
b > 1