Our function is . Notice that our possible roots are when x + 4 = 0 and when x + 7 = 0. So, our roots are -4 and -7.
However, the power above x + 4 is even, meaning the graph will simply <em>touch</em> the x-axis at x = -4, but not pass through. The power above x + 7, though, is odd, which means the graph will <em>cross</em> the x-axis.