Algebra
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If x = – 1, then the value of 1 + 1 + 1 + 1 + 1 + 1 + 1 - 1 is x99 x98 x97 x96 x95 x94 x
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On putting x = -1
1 = 1 = -1 x99 (-1)99 1 = 1 = 1 x98 (-1)98 1 = 1 = -1 and so on. x97 (-1)97
∴ Expression = – 1 + 1 – 1 + 1 – 1 + 1 – 1 – 1 = – 2Correct Option: C
On putting x = -1
1 = 1 = -1 x99 (-1)99 1 = 1 = 1 x98 (-1)98 1 = 1 = -1 and so on. x97 (-1)97
∴ Expression = – 1 + 1 – 1 + 1 – 1 + 1 – 1 – 1 = – 2
- If a + b + c = 0, then a3 + b3 + c3 is equal to
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Using Rule 21,
∴ a3 + b3 + c3 – 3abc = (a + b + c)(a2 + b2 + c2 – ab – bc – ca)
If a + b + c = 0, then a3 + b3 + c3 = 3abcCorrect Option: D
Using Rule 21,
∴ a3 + b3 + c3 – 3abc = (a + b + c)(a2 + b2 + c2 – ab – bc – ca)
If a + b + c = 0, then a3 + b3 + c3 = 3abc
- If a + b + c = 0, then a3 + b3 + c3 is equal to
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View Hint View Answer Discuss in Forum
Using Rule 21,
∴ a3 + b3 + c3 – 3abc = (a + b + c)(a2 + b2 + c2 – ab – bc – ca)
If a + b + c = 0, then a3 + b3 + c3 = 3abcCorrect Option: D
Using Rule 21,
∴ a3 + b3 + c3 – 3abc = (a + b + c)(a2 + b2 + c2 – ab – bc – ca)
If a + b + c = 0, then a3 + b3 + c3 = 3abc
- If a = 4.965, b = 2.343 and c = 2.622, then the value of a3 - b3 - c3 – 3abc is :
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Using Rule 21,
If a + b + c = 0, then a3 + b3 + c3 = 3abc
∴ When a – b – c = 0,
a3 - b3 - c3 = 3abc
i.e. a3 - b3 - c3 - 3abc = 0
Here,a = 4.965, b = 2.343, c = 2.6222
∴ a – b – c = 4.965 – 2.343 – 2.622 = 0
Hence, a3 - b3 - c3 - 3abc = 0Correct Option: C
Using Rule 21,
If a + b + c = 0, then a3 + b3 + c3 = 3abc
∴ When a – b – c = 0,
a3 - b3 - c3 = 3abc
i.e. a3 - b3 - c3 - 3abc = 0
Here,a = 4.965, b = 2.343, c = 2.6222
∴ a – b – c = 4.965 – 2.343 – 2.622 = 0
Hence, a3 - b3 - c3 - 3abc = 0
- If a = 1.21, b = 2.12 and c = –3.33, then the value of a3 - b3 - c3 – 3abc is
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Using Rule 21,
Here, a + b + c = 1.21 + 2.12 – 3.33 = 0
a3 - b3 - c3 - 3abc = 0 ( ∴ a + b + c = 0)Correct Option: A
Using Rule 21,
Here, a + b + c = 1.21 + 2.12 – 3.33 = 0
a3 - b3 - c3 - 3abc = 0 ( ∴ a + b + c = 0)