Question 1209271
**1. Combine Like Terms**

* y = -2x² + 8x - 15 - 5x² + 17x + 20
* y = -7x² + 25x + 5

**2. Find the Vertex**

* **Vertex Formula:** For a parabola in the form y = ax² + bx + c, the vertex is given by:
    * x-coordinate of the vertex: x = -b / 2a

* **In this case:**
    * a = -7
    * b = 25
    * x = -25 / (2 * -7) = 25/14

* **Find the y-coordinate of the vertex:**
    * Substitute the x-coordinate of the vertex back into the equation:
        * y = -7(25/14)² + 25(25/14) + 5 
        * y = -7(625/196) + 625/14 + 5
        * y = -225/28 + 625/14 + 5
        * y = 225/7 + 5 
        * y = 265/7

**Therefore, the vertex of the graph is (25/14, 265/7).**