Answer
$(-1,6)$.
Work Step by Step
$x^2-3x\lt 6+2x$,
$x^2-5x-6\lt0$,
$(x+1)(x-6)\lt 0$,
The $\lt$ sign indicates that the solution will be within the region formed by the boundary points $x=-1, 6$, thus we have the solution interval $(-1,6)$.