SOLUTION: x^2+kx+36 what is the value of k for which the expression is a perfect square trinomial

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Question 977321: x^2+kx+36 what is the value of k for which the expression is a perfect square trinomial
Found 3 solutions by Alan3354, josgarithmetic, MathTherapy:
Answer by Alan3354(69443)   (Show Source):
You can put this solution on YOUR website!
x^2+kx+36 what is the value of k for which the expression is a perfect square trinomial
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It's ax^2 + bx + 36
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For a perfect sq trinomial,
c = (b/2)^2
c = b^2/4

k = b

Answer by josgarithmetic(39617)   (Show Source):
You can put this solution on YOUR website!
k=12 or k=-12, but you probably want to see some steps.

You are looking for (x+6)(x+6) because you know you want the constant term to be 36. You can also try using descriminant, but that should not be needed for this simple example.

Answer by MathTherapy(10552)   (Show Source):
You can put this solution on YOUR website!

x^2+kx+36 what is the value of k for which the expression is a perfect square trinomial

Complete the square to get a perfect square trinomial

This means that:

------ Taking square root of both sides

------- Cross-multiplying