Answer:
(x-5)^2+2
Explanation:
To convert between standard and vertex form, you have to complete the square (which, as a reminder, (a+b)^2 = a^2+2ab+b^2).
Since a^2 is x^2, and 2ab is -10x, then b must be -5, so b^2 is 25. Therefore, we add and subtract 25 from the expression:
(x-10x+25)+27-25
Then, we can make (x-10x+25) to (x-5)^2:
(x-5)^2+2