Multiple choice

Find the approximate value of the question mark (?) in the given below question. (40.01^2 - 23.98^2 - ? = 31.97^2)

  1. 4

  2. 12

  3. 32

  4. 36

  5. 0
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Rearrange: ? = 40.01² - 23.98² - 31.97². Calculate: 40.01² ≈ 1600.8; 23.98² ≈ 575.04; 31.97² ≈ 1022.08; So ? = 1600.8 - 575.04 - 1022.08 = 3.68 ≈ 0 (option E). This uses the identity a² - b² - c² when values approximately satisfy c² ≈ (a² - b²).

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