The x-intercept of a graph is the point where the graph crosses the x-axis
<h3>(a) Graph</h3>
The function is given as:

See attachment for the graph of the function.
From the attachment, the approximated x-intercepts are -7 and -1
<h3>(b) Type of solution</h3>
From the attached graph, we can see that the curve crosses the x-axis at non-terminating decimals
Hence, the solutions of the equation are irrational.
<h3>(c) The vertex</h3>
This is the minimum or the maximum point of a parabola.
From the attached graph, the minimum point is at (-4,-7)
Hence, the coordinates of the vertex of the parabola is (-4,-7), and it is exact (not approximated)
Read more about parabolas at:
brainly.com/question/4061870