# Algebra need help

I do not know how to do this - also please explain...
What is the value of c so that y = x² + 9x + c is a perfect square trinomial?

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1. perfect square?

x^2 + 9x + (9/2)^2 is the perfect trinomial, isn't it?
(x+9/2)^2 FOIL it out...

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👨‍🏫
bobpursley

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