Algebrahard · Past Paper
If f(x) = x^2 - 5x + 7, find f(x+1) - f(x).
A2x - 4
B2x + 4
Cx - 5
D2x - 5
✓ Correct Answer: A — 2x - 4
f(x+1) = (x+1)^2 - 5(x+1) + 7 = x^2+2x+1-5x-5+7 = x^2-3x+3. Subtracting f(x): (x^2-3x+3)-(x^2-5x+7) = 2x-4.
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