SOLUTION: Given f(x) = 5x2 – 3x + 1, find f(–2).

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Question 92290: Given f(x) = 5x2 – 3x + 1, find f(–2).
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
f%28x%29=5x%5E2-3x%2B1 Start with the given polynomial


f%28-2%29=5%28-2%29%5E2-3%28-2%29%2B1 Plug in x=-2


f%28-2%29=5%284%29-3%28-2%29%2B1 Raise -2 to the second power to get 4


f%28-2%29=20-3%28-2%29%2B1 Multiply 5 by 4 to get 20


f%28-2%29=20--6%2B1 Multiply 3 by -2 to get -6


f%28-2%29=20%2B6%2B1 Negate any negatives


f%28-2%29=27 Now combine like terms


So when x=-2, f%28-2%29=27