How to find the value c that completes the square of a quadratic, x^2 - 20x + c

The video tutorial explains how to complete the square for a trinomial to form a perfect square. It begins by introducing the concept of finding the value C that completes the trinomial. The process involves taking half of the coefficient B, squaring it, and using this value to form a perfect square trinomial. The tutorial then demonstrates how to factor the trinomial into its factored form and discusses the vertex form of the equation. The lesson concludes with a brief Q&A session.

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