You can
put this solution on YOUR website!find the intercepts and vertex for
When x=0, y=0.
When y=0,

x = 0 or x = -4.
Hence the intercept points are (0,0) and (-4,0)

Hence the vertex is (-2,4)
find intercept for x^3-2x^2-9x=18=0

x = 2 , 3 or -3
Hence the intercepts are (2,0) , (3,0) and (-3,0)