How do I continue?
If you want to find the solutions without reference to the graphs, you can reason thus...
is positive if
as that causes both factors to be positive
or is positive if
as that causes both factors to be negative.
If x is in between 4 and 11, one factor is negative and the other positive.
For both factors are positive if
and both factors are negative if
Hence, the factors have opposite sign if x is between 1 and 2.