Directions: Find the value of C that makes the expression a perfect square trinomial. Then write the expression as the square of a binomial.
Problem: x² + 6x + c
A perfect square trinomial will always be in the following form: $\displaystyle (a + b) = a^2 + 2ab + b^2$
For your problem a is clearly equal to x. The linear term is then 6x = 2ab = 2(x)b. Thus we may identify 2b = 6. That makes b = 3. Can you finish this?