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Evalute: (38)^(2) - (37)^(2) (75)^(...

Evalute:
`(38)^(2) - (37)^(2)`
`(75)^(2)-(74)^(2)`
`(92)^(2) -(91)^(2)`
`(105)^(2)-(104)^(2)`
`(141)^(2) - (140)^(2)`
`(218)^(2) -(217)^(2)`

Text Solution

AI Generated Solution

The correct Answer is:
To evaluate the expressions given, we can use the algebraic identity for the difference of squares, which states: \[ a^2 - b^2 = (a + b)(a - b) \] We will apply this identity to each of the expressions provided. ### Step-by-Step Solution: 1. **Evaluate \( (38)^2 - (37)^2 \)**: - Here, \( a = 38 \) and \( b = 37 \). - Using the identity: \[ (38)^2 - (37)^2 = (38 + 37)(38 - 37) \] - Calculate \( 38 + 37 = 75 \) and \( 38 - 37 = 1 \). - Therefore, \[ (38)^2 - (37)^2 = 75 \times 1 = 75 \] 2. **Evaluate \( (75)^2 - (74)^2 \)**: - Here, \( a = 75 \) and \( b = 74 \). - Using the identity: \[ (75)^2 - (74)^2 = (75 + 74)(75 - 74) \] - Calculate \( 75 + 74 = 149 \) and \( 75 - 74 = 1 \). - Therefore, \[ (75)^2 - (74)^2 = 149 \times 1 = 149 \] 3. **Evaluate \( (92)^2 - (91)^2 \)**: - Here, \( a = 92 \) and \( b = 91 \). - Using the identity: \[ (92)^2 - (91)^2 = (92 + 91)(92 - 91) \] - Calculate \( 92 + 91 = 183 \) and \( 92 - 91 = 1 \). - Therefore, \[ (92)^2 - (91)^2 = 183 \times 1 = 183 \] 4. **Evaluate \( (105)^2 - (104)^2 \)**: - Here, \( a = 105 \) and \( b = 104 \). - Using the identity: \[ (105)^2 - (104)^2 = (105 + 104)(105 - 104) \] - Calculate \( 105 + 104 = 209 \) and \( 105 - 104 = 1 \). - Therefore, \[ (105)^2 - (104)^2 = 209 \times 1 = 209 \] 5. **Evaluate \( (141)^2 - (140)^2 \)**: - Here, \( a = 141 \) and \( b = 140 \). - Using the identity: \[ (141)^2 - (140)^2 = (141 + 140)(141 - 140) \] - Calculate \( 141 + 140 = 281 \) and \( 141 - 140 = 1 \). - Therefore, \[ (141)^2 - (140)^2 = 281 \times 1 = 281 \] 6. **Evaluate \( (218)^2 - (217)^2 \)**: - Here, \( a = 218 \) and \( b = 217 \). - Using the identity: \[ (218)^2 - (217)^2 = (218 + 217)(218 - 217) \] - Calculate \( 218 + 217 = 435 \) and \( 218 - 217 = 1 \). - Therefore, \[ (218)^2 - (217)^2 = 435 \times 1 = 435 \] ### Final Results: - \( (38)^2 - (37)^2 = 75 \) - \( (75)^2 - (74)^2 = 149 \) - \( (92)^2 - (91)^2 = 183 \) - \( (105)^2 - (104)^2 = 209 \) - \( (141)^2 - (140)^2 = 281 \) - \( (218)^2 - (217)^2 = 435 \)
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RS AGGARWAL-SQUARES-EXERCISE 3B
  1. Which of the are square of even number ? 196 441 900 625 32...

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  2. Without adding, find the sum: (1+3+5+7+9+11+13) (1+3+5+7+9+11+13+1...

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  3. Express 81 as the sum of 9 odd numbers.

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  4. Express 100 as the sum of 10 odd numbers.

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  5. Write the Pythagorena triplet whose smallest number is 6 14 16 ...

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  6. Evalute: (38)^(2) - (37)^(2) (75)^(2)-(74)^(2) (92)^(2) -(91)^(2...

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  7. Using the formula (a+b)^(2) = (a^(2) + 2ab+b ^(2)), evaluate: (310)^...

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  8. Evaluate: 69xx71

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  9. Evaluate: 94xx106

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  10. Evaluate: 88xx92

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  11. Evaluate: 78xx82

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  12. Fill in the blanks: The square of an even number is ………

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  13. Fill in the blanks: The square of an odd number is ……….

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  14. Fill in the blanks: The square of a proper fraction is ……. than the ...

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  15. Fill in the blanks: n^(2)= the sum of first n……….natural numbers.

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  16. Write (T) for true and (F) for false for each of the statements given ...

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  17. Write (T) for true and (F) for false for each of the statements given ...

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  18. Write (T) for true and (F) for false for each of the statements given ...

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  19. Write (T) for true and (F) for false for each of the statements given ...

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  20. Write (T) for true and (F) for false for each of the statements given ...

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