what is the vertex and the x-intercepts of the function -2x^2+4x+6?

$$\\y=-2x^2+4x+6\\ y=-2(x^2-2x-3)\\ $concave down because of the neg coeff of $ x^2\\ y=-2(x+1)(x-3)\\ $roots are x=-1 and x=3$\\ $axis of symmetry $x=\frac{-1+3}{2}=1\\ $Vertex y value$\\ y=-2*1^2+4*1+6)=-2+4+6=8\\ vertex \;\;(1,8)$$

If you graph the equation (assuming that it is equal to zero), you will see that the x-intercepts are -1 and 3.

These can also be determined through the quadratic equation.

The vertex is (1,8), using -b/2a you can get the x-value of the vertex and then insert it into the equation to get the y-value.

Here's the graphical solution that confirms Anonymous' answers

https://www.desmos.com/calculator/fbm3sesyex