In order to make the equation a perfect square trinomial, you must add 9 to both sides of the equation. Adding 9 to the left side would give you x2 - 6x + 9 = (x-3)2. Adding 9 allows you to break the left side down into two identical terms of x-3 which are multiplied together. The right side is left with 10 by adding 9. Final answer would be x2-6x+9=10
