When forming a perfect square trinomial you need to "complete the square".
All of the steps to completing the square when solving an equation:
1. The leading coefficient must be 1.
2. Divide b by 2.
3. Square (b/2)
4. Add (b/2)^2 to both sides to keep the polynomial balanced.
5. You can now write the perfect square trinomial and solve.
x^2 - 3x
-3/2
(-3/2)^2 = 9/4 = 2 1/4
LETTER B