Answer
See below
Work Step by Step
Make a table of $x$ and $y$ values that contains locations where $y=x^2+6x-8$ to solve using a table. Intervals will be separated by when $y=0$. The answer is found in the intervals when y is negative.
To solve by graphing, graph $y=x^2+6x-8$. The solution will be values of x where the graph is below the $x$ axis $(y=0)$.
To solve algebraically, solve the equation $0=x^2+6x-8$ for $x$. Test an $x$ value in the equation to check if it is positive or negative in the intervals separated by those x values. The solutions are the negative intervals.