Michelle needs to convert the function f(x) = x2 - 10x +31 to vertex form, fx) = (x - 1)2 + k, in order to find the minimum. When she does this, what is the value of k in the vertex form of function ?
26
56
31
6

To find k

You can do

C-a((b/2)^2))

This is because when you complete the square you have the c value that you have initially minus the new c value which is found by (b/2)^2 and if you factored a number out then multiply it to that.

So in this case

31- 1(10/2)^2

31-(5)^2

31-25

6