It must be between 900 and 1000 because
900^2 = 810,000 < 894,916 < 1,000,000
(900 + a)^2 = 894,916
810,000 + 1,800a + a^2 = 894,916
a^2 + 1,800a = 84,916
let a be (10b + c), where b is a natural number between 0 and 9, and c<10
(10b + c)^2 + 1800*(10b + c) = 100b^2 + 20bc + c^2 +
+ 18,000b + 1,800c
100b^2 + 20bc + c^2 + 18,000b + 1,800c = 84,916
If b=5 18,000 * 5 = 90,000 > 84,916, thus b must be smaller than 5
Try b=4
100*4^2 + 20*4c + c^2 + 18,000 * 4 + 1,800c = 84,916
1,600 + 80c + c^2 + 72,000 + 1,800c = 84,916
c^2 + 1,880c + 73,600 = 84,916
c^2 + 1,880c = 11,316
11,316 / 1880 = 6.019 ...
Try c=6
6^2 + 1,880c = 36 + 11,280 = 11,316 -- Bingo!
900 + 10*b + c = 946
946^2 = 894,916
2007-12-12 01:53:24
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answer #2
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answered by Amit Y 5
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I have no calculator.
â894916 > 945 as 945^2 = (94*95)25 = 893025
â894916 < 950 as 950^2 = (9*10)2500 = 902500
=> â894916 = 946
2007-12-12 01:50:00
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answer #4
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answered by sv 7
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= â894,916
= 946
Answer: 946
2007-12-12 01:34:25
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answer #5
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answered by Jun Agruda 7
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