# Which value must be added to the expression x^{2} + x to make it a perfect square trinomial?

A perfect square trinomial is the one, which gives specific roots value when square rooted.

## Answer: We need to add 1/4(c^{2}) to the expression x^{2} + x to make it a perfect square.

Go through the explanation to understand the steps involved.

**Explanation:**

Let the unknown constant value be c^{2}, that will make it a perfect square.

⇒ x^{2} + x + c^{2}

Comparing this to a perfect square, that is, a^{2} + 2ab + b^{2}, we get

x = 2ab, x = a, c = b

The value of b comes out to be equal to 1/2 which is also equal to c.