Given the increasing function of F (x) in the domain of definition [- 2,1], f (t-1) < f (1-3T) can find the range of T

Given the increasing function of F (x) in the domain of definition [- 2,1], f (t-1) < f (1-3T) can find the range of T

The domain of F (x) is [- 2,1], so - 2