Question

For x*3–4x*2—5x find
a) range
b) intercept

Answer 1

for all polynomials of odd degree, the range is all real numbers -- think of the shape of y=x, y=x^3, and so on.
y = x(x-5)(x+1)
The y-intercept is (0,0)
and you can just read off the x-intercepts ...