We have

where
a=1
b=-2
c=-5
First we need to find the vertex, with the next formula we will find the x-coordinate of the vertex.

we substitute the values

then we substitute the value of the x-coordinate in the original equation in order to find the y-coordinate

the coordinates of the vertex is (1,-6)
the vertex form of the parabola is

where h is the x-coordinate of the vertex and k is the y-coordinate of the vertex, the vertex form of this parabola is
