ExamHoot

Find the value of 17+122+17122\sqrt{17 + 12\sqrt{2}} + \sqrt{17 - 12\sqrt{2}}.

  1. 66

  2. 88

  3. 44

  4. 2172\sqrt{17}

Show answer & explanation

Correct answer

66

Explanation

Let x=17+122+17122x = \sqrt{17 + 12\sqrt{2}} + \sqrt{17 - 12\sqrt{2}}. Squaring: x2=17+122+17122+2(17)2(122)2=34+2289288=34+2=36x^2 = 17 + 12\sqrt{2} + 17 - 12\sqrt{2} + 2\sqrt{(17)^2 - (12\sqrt{2})^2} = 34 + 2\sqrt{289 - 288} = 34 + 2 = 36. So x=6x=6 (positive).

Written by ExamHoot EditorialPublished · Updated

All 20 Simplification questions

  1. 1.Simplify:
  2. 2.Find the value of 17 + 12√2 + 17 - 12√2 .
  3. 3.Simplify:
  4. 4.Approximately evaluate 49.8 × 20.1 × 0.98/4.9 × 9.9 × 3.1 using rounding to one significant figure.
  5. 5.Simplify:
  6. 6.If x = 2 + √3 , find the value of x^2 + 1/x^2 .
  7. 7.Simplify:
  8. 8.Find the value of 12 + 12 + √12 + .
  9. 9.Simplify:
  10. 10.Approximately what is 23.8\% of 489.6 ?
  11. 11.What value should come in place of the question mark ( ?
  12. 12.Evaluate the value of ?
  13. 13.Find the value of ?
  14. 14.What should come in place of ?
  15. 15.Find the value of ?
  16. 16.What value should come in place of the question mark ( ?
  17. 17.Find the value of ?
  18. 18.What should come in place of in the given expression?
  19. 19.Find the value of ?
  20. 20.Evaluate the value of ?