SOLUTION: Describe three different ways to solve x^2 - 2x - 15 = 0. Which method do you prefer and why? Thanks!

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Question 1025972: Describe three different ways to solve x^2 - 2x - 15 = 0. Which method do you prefer and why? Thanks!
Found 2 solutions by Fombitz, MathTherapy:
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Graphing.
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Completing the square.
x%5E2-2x-15=0
x%5E2-2x%2B1-15=1
%28x-1%29%5E2=16
x-1=0+%2B-+4
x=1+%2B-+4
x=-3 and x=5
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Quadratic equation.
x+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29+
x+=+%28-%28-2%29+%2B-+sqrt%28+%28-2%29%5E2-4%2A%281%29%2A9%28-15%29+%29%29%2F%282%2A1%29+
x+=+%282+%2B-+sqrt%28+4%2B60%29+%29%29%2F%282%29+
x+=+%282+%2B-+sqrt%28+64+%29%29%2F%282%29+
x+=+%282+%2B-8%29%2F%282%29+
x=1+%2B-+4
x=-3 and x=5
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Completing the square.
Gives an exact answer and also can give max/min values from vertex form.
More information than the other two methods.

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

Describe three different ways to solve x^2 - 2x - 15 = 0. Which method do you prefer and why? Thanks!
Of the 3 methods, I prefer FACTORING, in this case, and in may other cases, when the trinomial can be factored with INTEGERS.

x%5E2+-+2x+-+15+=+0

(x - 5)(x + 3) -------- Factoring the trinomial

highlight_green%28matrix%281%2C3%2C+x+=+5%2C+and%2C+x+=+-+3+%29%29