Home
Class 9
MATHS
Evaluate : (i) (98)^(3) " " (ii) (59...

Evaluate :
`(i) (98)^(3) " " (ii) (598)^(3) " " (iii) (1003)^(3)`

Text Solution

AI Generated Solution

The correct Answer is:
To evaluate the cubes of the numbers given in the question, we will use the identities for the cube of a binomial. ### Step-by-Step Solution: **(i) Evaluate \( (98)^3 \)** 1. **Rewrite 98 as a binomial**: \[ 98 = 100 - 2 \] Thus, we can express \( (98)^3 \) as: \[ (98)^3 = (100 - 2)^3 \] 2. **Apply the identity for \( (a - b)^3 \)**: The formula is: \[ (a - b)^3 = a^3 - 3a^2b + 3ab^2 - b^3 \] Here, \( a = 100 \) and \( b = 2 \): \[ (100 - 2)^3 = 100^3 - 3 \cdot 100^2 \cdot 2 + 3 \cdot 100 \cdot 2^2 - 2^3 \] 3. **Calculate each term**: - \( 100^3 = 1000000 \) - \( 3 \cdot 100^2 \cdot 2 = 3 \cdot 10000 \cdot 2 = 60000 \) - \( 3 \cdot 100 \cdot 2^2 = 3 \cdot 100 \cdot 4 = 1200 \) - \( 2^3 = 8 \) 4. **Combine the results**: \[ (98)^3 = 1000000 - 60000 + 1200 - 8 \] \[ = 1000000 - 60000 = 940000 \] \[ = 940000 + 1200 = 941200 \] \[ = 941200 - 8 = 941192 \] **Final Result for (i)**: \[ (98)^3 = 941192 \] --- **(ii) Evaluate \( (598)^3 \)** 1. **Rewrite 598 as a binomial**: \[ 598 = 600 - 2 \] Thus, we can express \( (598)^3 \) as: \[ (598)^3 = (600 - 2)^3 \] 2. **Apply the identity for \( (a - b)^3 \)**: Here, \( a = 600 \) and \( b = 2 \): \[ (600 - 2)^3 = 600^3 - 3 \cdot 600^2 \cdot 2 + 3 \cdot 600 \cdot 2^2 - 2^3 \] 3. **Calculate each term**: - \( 600^3 = 216000000 \) - \( 3 \cdot 600^2 \cdot 2 = 3 \cdot 360000 \cdot 2 = 2160000 \) - \( 3 \cdot 600 \cdot 2^2 = 3 \cdot 600 \cdot 4 = 7200 \) - \( 2^3 = 8 \) 4. **Combine the results**: \[ (598)^3 = 216000000 - 2160000 + 7200 - 8 \] \[ = 216000000 - 2160000 = 213840000 \] \[ = 213840000 + 7200 = 213847200 \] \[ = 213847200 - 8 = 213847192 \] **Final Result for (ii)**: \[ (598)^3 = 213847192 \] --- **(iii) Evaluate \( (1003)^3 \)** 1. **Rewrite 1003 as a binomial**: \[ 1003 = 1000 + 3 \] Thus, we can express \( (1003)^3 \) as: \[ (1003)^3 = (1000 + 3)^3 \] 2. **Apply the identity for \( (a + b)^3 \)**: Here, \( a = 1000 \) and \( b = 3 \): \[ (1000 + 3)^3 = 1000^3 + 3 \cdot 1000^2 \cdot 3 + 3 \cdot 1000 \cdot 3^2 + 3^3 \] 3. **Calculate each term**: - \( 1000^3 = 1000000000 \) - \( 3 \cdot 1000^2 \cdot 3 = 3 \cdot 1000000 \cdot 3 = 9000000 \) - \( 3 \cdot 1000 \cdot 3^2 = 3 \cdot 1000 \cdot 9 = 27000 \) - \( 3^3 = 27 \) 4. **Combine the results**: \[ (1003)^3 = 1000000000 + 9000000 + 27000 + 27 \] \[ = 1000000000 + 9000000 = 1009000000 \] \[ = 1009000000 + 27000 = 1009027000 \] \[ = 1009027000 + 27 = 1009027027 \] **Final Result for (iii)**: \[ (1003)^3 = 1009027027 \] --- ### Summary of Results: 1. \( (98)^3 = 941192 \) 2. \( (598)^3 = 213847192 \) 3. \( (1003)^3 = 1009027027 \)
Promotional Banner

Topper's Solved these Questions

  • POLYNOMIALS

    NAGEEN PRAKASHAN ENGLISH|Exercise Revision Exercise (very Short Answer Questions)|10 Videos
  • POLYNOMIALS

    NAGEEN PRAKASHAN ENGLISH|Exercise Revision Exercise (short Answer Questions)|16 Videos
  • POLYNOMIALS

    NAGEEN PRAKASHAN ENGLISH|Exercise Exercise 2d|5 Videos
  • NUMBER SYSTEM

    NAGEEN PRAKASHAN ENGLISH|Exercise Revision Exercise (short Answer Questions)|10 Videos
  • PROBABILITY

    NAGEEN PRAKASHAN ENGLISH|Exercise Revision Exercise (very Short Answer /short Answer Questions)|10 Videos

Similar Questions

Explore conceptually related problems

Evaluate : (i) (a+6b)^(2) " " (ii) (3x-4y)^(2) " " (iii) (2a-b+c)^(2)

Expand : (i) (2x+3y)^(3) " " (ii) (5y-3x)^(3) " " (iii) (2a+3b)^(3) .

Evaluate: (i) 8! (ii) 4! - 3!

Evaluate (i) 8! (ii) 4! 3!

Evaluate each of the following: (10. 4)^3 (ii) (598)^3 (iii) (99)^3

Evaluate each of the following: (i) (103)^3 (ii) (98)^3 (iii) (9. 9)^3

Find the valency factor for following bases : (i) Ca(OH)_(2) " " (ii) CsOH " " (iii) Al(OH)_(3)

Evaluate. (i) 3^(-2) (ii) (-4)^(-2) (iii) (1/2)^(-5)

Evaluate : (i) 5^(-2) (ii) (-3)^(-2) (iii) (1/4)^(-1) (iv) ((-1)/2)^(-1)

Evaluate each of the following by removing radical signs and negative indices wherever they occur: (i)\ (64)^(1/3) (ii) (125)^(-1/3) (iii)\ (27)^(-2/3) (iv) ((64)/(25))^(-3/2)

NAGEEN PRAKASHAN ENGLISH-POLYNOMIALS-Exercise 2 E
  1. Evaluate without multiplying directly : (i) 33xx27 " " (ii) 103xx9...

    Text Solution

    |

  2. Expand : (i) (3a-5b)^(2) " " (ii) (a+(1)/(a))^(2) " " (iii) (2x-(...

    Text Solution

    |

  3. Expand : (i) (a+b-c)^(2) " " (ii) (a-2b-5c)^(2) " " (iii) (3a-2b...

    Text Solution

    |

  4. Evaluate using formula : (i) (188)^(2) " " (ii) (9.4)^(2) " " (i...

    Text Solution

    |

  5. (i) If a^(2)+b^(2)+c^(2)=20 " and" a+b+c=0, " find " ab+bc+ac. (ii) ...

    Text Solution

    |

  6. Expand : (i) (2x+3y)^(3) " " (ii) (5y-3x)^(3) " " (iii) (2a+3b)...

    Text Solution

    |

  7. Evaluate (2x-3y+5)^(3).

    Text Solution

    |

  8. If a+2b=5, then show that a^(3)+8b^(3)+30ab=125.

    Text Solution

    |

  9. If 2x-3y=10 and xy=16, find the value of 8x^(3)-27y^(3).

    Text Solution

    |

  10. Evaluate : (i) (98)^(3) " " (ii) (598)^(3) " " (iii) (1003)^(3)

    Text Solution

    |

  11. Factorise : 4a^(2)+9b^(2)+16c^(2)+12ab-24bc-16ca

    Text Solution

    |

  12. Verify : (i) x^3+y^3=(x+y)(x^2-x y+y^2) (ii) x^3-y^3=(x-y)...

    Text Solution

    |

  13. Factorise : (i) 9a^(3)-27b^(3) " " (ii) a^(3)-343 " " (iii) a^(...

    Text Solution

    |

  14. Find the product : (i) (x+3)(x^(2)-3x+9) " " (ii) (7+5b)(49-35b+2...

    Text Solution

    |

  15. Factorise : (i) a^(3)+27b^(3)+8c^(3)-18abc " " (ii) 2sqrt(2)a^(3)...

    Text Solution

    |

  16. Find the product : (i) (a+2b+4c)(a^(2)+4b^(2)+16c^(2)-2ab-8bc-4ca) ...

    Text Solution

    |

  17. Factorise : (i) (x-y)^(3)+(y-z)^(3)+(z-x)^(3) (ii) (x-2y)^(3)+(2y-...

    Text Solution

    |

  18. Without actually calculating the cube find the value of the following ...

    Text Solution

    |

  19. Verify that x^3+y^3+z^3-3xyz=1/2(x+y+z)[(x-y)^2+(y-z)^2+(z-x)^2]

    Text Solution

    |

  20. If x+y+z=0show that x^3+y^3+z^3=3x y z.

    Text Solution

    |