
b) The function has three x-intercepts (when f(x) = 0): in x = -10, x = 0 and x = 10
It also has one y-intercept, in (x,y) = (0,0)
c) The least zero is a zero of multiplicity 1, so the graph of f crosses the x-axis at x = -10. The middle zero is a zero of multiplicity 2, so the graph of f touches the x-axis at x = 0. The gratest zero is a zero of multiplicity 1, so the graph of f crosses the x-axis at x = 10.