<h3>
Answer: B. f(x) = x^2-4x+7</h3>
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Work Shown:
A.
f(x) = 3x-8
f(5) = 3*5-8 ... replace every x with 5; simplify with PEMDAS
f(5) = 15-8
f(5) = 7
We can cross choice A off the list since we got 7 as an output, instead of 12.
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B.
f(x) = x^2-4x+7
f(5) = (5)^2-4(5)+7
f(5) = 25-4(5)+7
f(5) = 25-20+7
f(5) = 5+7
f(5) = 12
We got the output we wanted. So we can stop here.
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If you're curious about the others, then,
C.
f(x) = -x+14
f(5) = -5+14
f(5) = 9
That doesn't work, so we cross choice C off the list.
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D.
f(x) = |x-7|
f(5) = |5-7|
f(5) = |-2|
f(5) = 2
Choice D is crossed out as well.
So only choice B works.
