You can put this solution on YOUR website! 3x^2-11x+6<=0
(3x-2)(x-3)=0 solve for this first
x=2/3,3
The vertex is where x=-b/2a=11/6, which is midway between the two roots. The y-value at the vertex is negative.
This is a parabola with those two values the roots. They are critical values where the parabola equals 0. If you choose a number in between, say 1, you get a negative value. Therefore, between and including those roots, the y-value is less than or equal to 0 and is the solution.