Find the value of c that makes each trinomial a perfect square. Then write the trinomial as a perfect square.
A trinomial that was a perfect square (with a leading coefficient of 1) is formed by multiplying (x + a)(x + a) to get x2 + 2ax + a2. Looking at the linear coefficient of our original equation, 2a = 11, so a = 11/2. We then square this to get a2 = (11/2)2 = 121/4
So our new trinomial is x2 + 11x + 121/4