InterviewSolution
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InterviewSolution
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Evaluate the following, using suitable identity.(i) 512(ii) 1032(iii) 9982(iv) 472 |
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Answer» (i) 512 = (50 + 1)2 Taking a = 50 and b = 1 we get (a + b)2 = a2 + 2ab + b2 (50 + 1)2 = 502 + 2 (50) (1) + 12 = 2500 + 100 + 1 512 = 2601 (ii) 1032 1032 = (100 + 3)2 Taking a = 100 and b = 3 (a + b)2 = a2 + 2ab + b2 becomes (100 + 3)2 = 1002 + 2 (100) (3) + 32 = 10000 + 600 + 9 1032 = 10609 (iii) 9982 9982 = (1000 – 2)2 Taking a = 1000 and b = 2 (a – b)2 = a2 + 2ab + b2 becomes (1000 – 2)2 = 10002 – 2 (1000) (2) + 22 = 1000000 – 4000 + 4 9982 = 10,04,004 (iv) 472 472 = (50 – 3)2 Taking a = 50 and b = 3 (a – b)2 = a2 – 2ab + b2 becomes (50 – 3)2 = 502 – 2 (50) (3) + 32 = 2500 – 300 + 9 = 2200 + 9 472 = 2209 |
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