Question 1018622
3x^2 + 16x + 3 
This doesn't factor.  (3x+1)(x+3) gives the largest x value which is only 10x.
3x^2+16x+13 does factor into (3x+13)(x+1)
quadratic formula 
x=(1/6)*(-16+/- sqrt (256-36)); sqrt 220=14.83, so no integer roots. (numerically about -.23 and -5.14)
{{{graph(300,200,-10,10,-10,10,3x^2+16x+3)}}},