Mathematics
Using suitable identity, evaluate :
(i) (104)3
(ii) (97)3
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Answer
(i) Given,
⇒ (104)3
⇒ (100 + 4)3
Using identity :
(a + b)3 = a3 + b3 + 3ab(a + b)
⇒ (100 + 4)3 = (100)3 + 43 + 3 × 100 × 4 × (100 + 4)
⇒ (100 + 4)3 = 1000000 + 64 + 124800
⇒ 1124864.
Hence, (104)3 = 1124864.
(ii) Given,
⇒ (97)3
⇒ (100 - 3)3
⇒ (100)3 - 33 - 3 × 100 × 3 × (100 - 3)
⇒ 1000000 - 27 - 900 × 97
⇒ 1000000 - 27 - 87300
⇒ 912673.
Hence, (97)3 = 912673.
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