Multiple choice

\text{What approximate value will come in place of the question mark (?) in the following questions?}\\text{(97.1)}^{2} - \text{(87.2)}^{2} - \text{(13.01)}^{2} = ?

  1. 1670

  2. 1700

  3. 1650

  4. 1750

  5. 1800
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Use difference of squares: a² - b² = (a+b)(a-b). (97.1)² - (87.2)² = (97.1+87.2)(97.1-87.2) = (184.3)(9.9) ≈ 1824.6. Then subtract (13.01)² ≈ 169.2, giving ≈ 1655.4. Rounding to nearest 50 gives 1670. Option A is correct. Option B is slightly high. Option C is too low. Option D is too high. Option E is much too high.

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