Question 101240
Given:
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f(x) = 4x - 3
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The problem asks you to find f(-1).
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All that this is telling you to do is to evaluate f(x) when x equals -1. So, just go to the
given f(x) and substitute -1 for every x. 
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Starting with:
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f(x) = 4x - 3
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replacing every x by -1 results in:
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f(-1) = 4*(-1) - 3
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and since 4 times (-1) equals -4 the equation becomes:
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f(-1) = -4 - 3
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And on the right side the -4 and the -3 combine to -7. Therefore, the equation is finally 
reduced to:
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f(-1) = -7
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And this is the answer you were asked to find.
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Hope this helps you to understand how to do problems such as these by just substituting
for x the value given in the parentheses and then combining the terms as much as possible
to reduce the answer.