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Question
Evaluate using the formula:
793 + 3(79)2 + 3(79) + 1
Evaluate
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Solution
793 + 3(79)2 + 3(79) + 1
Here, a = 79
Using the identity:
a3 + 3a2 + 3a + 1 = (a + 1)3
Thus,
793 + 3(79)2 + 3(79) + 1 = (79 + 1)3
∴ (79 + 1)3 = (80)3
∴ 793 + 3(79)2 + 3(79) + 1 = 5,12,000
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Chapter 3: Expansions - EXERCISE B [Page 36]
