Given b = √7, what is (b+2)² + (b-2)²?

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Accepted Answer

1. Substitute $b=\sqrt{7}$ and expand:

$(b+2)^2+(b-2)^2=(b^2+4b+4)+(b^2-4b+4)$.

2. Combine like terms: the $4b$ terms cancel, so $=2b^2+8$.

3. Use $b^2=7$: $=2\cdot7+8=14+8=22$.

FINAL_ANSWER: c

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