SOlve the following inequalities:

1. x^2-x-6 greater than equal to zero

2. x^3+5x^2-4x-20 > 0

just solve as for equations. If you find the roots, then

for the parabola, y>=0 outside the interval containing the roots.

For the cubic, you know y<0 where x is less than the smallest root.

y>0 between the 1st and 2nd roots,
y<0 between the 2nd and 3rd roots
y>0 where x is greater than the 3rd root.