Answer:
the points (-5,0) and (3,0) are the x-intercepts of the parabola.
Explanation:
The equation of a parabola with vertex in (h,k) is:

Where p is a constant. Replacing the (h,k) by (-1,80), we get:

Additionally, we know that when x is 0, y is equal to 75. So, we can replace these values and solve for p as:

So, replacing the value of p on the initial equation, we get that the equation of the parabola is equal to:

Solving for y, we get:

Then, the x-intercepts of the parabola are the values of x where y is equal to zero, so we need to solving the following equation:

So, the values of x are calculated as:

Finally, the points (-5,0) and (3,0) are the x-intercepts of the parabola.