Find the vertex of the graph of the equation y = -2x^2 + 8x + 15 - 3x^2 + 7x - 25
Simplify as
y = -5x^2 + 15x - 10
x coordinate of the vertex = -15 / [ 2 * -5 ] = -15 / -10 = 3/2
y coordinate of the vertex = -5(3/2)^2 + 15(3/2) -10 = 5/4
+1212 
