SOLUTION: Given f(x)= 5x^2-3x+1, find f(-2)

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Question 125798: Given f(x)= 5x^2-3x+1, find f(-2)
Answer by bucky(2189) About Me  (Show Source):
You can put this solution on YOUR website!
To do this problem you start with the given function:
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f%28x%29=+5x%5E2-3x%2B1
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When you see f(-2) all that means is for you to go to the given function, replace every x with
-2 and simplify the answer.
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So you start with:
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f%28x%29=+5x%5E2-3x%2B1
.
wherever you see an x replace it with -2 and you get:
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f%28-2%29+=+5%28-2%29%5E2+-+3%28-2%29+%2B+1
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For the first term on the right side you square the -2 to get +4 and you multiply that
by 5 to get +20. For the second term on the right side you multiply the -3 by the -2 and
you get +6. Substituting these two results into the equation gives:
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f%28-2%29+=+20+%2B+6+%2B+1
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This means that the answer is:
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f%28-2%29+=+27
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And that's the answer to this problem.
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Hope this helps you to understand in general how, when you are given f(x), you can find
f(A) ... just substitute A wherever you see an x in f(x).