Multiple choice general knowledge math & puzzles

Let A = 3 + (the square root of 7) and let B = 3 - (the square root of 7). Then the product AB equals

  1. 2

  2. 4

  3. 10

  4. 16
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

AB = (3 + √7)(3 - √7) = 3² - (√7)² = 9 - 7 = 2. These are conjugates, and their product follows the difference of squares pattern (a + b)(a - b) = a² - b². This eliminates the radical term.

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