I need to find the trinomial value of k which makes a perfect square. The problem is x² - 6x + k

I hope this will help
My name is Lea

Part of solving algebra problems is seeing patterns and relationships. A trinomial that is a perfect square is of the form

The pattern to see here is the relationship between the the coefficient of x, 2a, and the constant term, a²; if you divide the coefficient of x by 2 and then square it you get the constant term. In your example the coefficient of x is -6 so the constant term is (-6/2)² = 9.