Pls answer this question quickly ........
let a,b,c be positive integers less than 10 such that (100a+10b+c)^2=(a+b+c)^5 what is (a^2+b^2+c^2)?
Answers
||✪✪ QUESTION ✪✪||
Let a,b,c be positive integers less than 10 such that (100a+10b+c)^2=(a+b+c)^5 what is (a^2+b^2+c^2) ? [ Excellent Question. ]
|| ✰✰ ANSWER ✰✰ ||
Given that, (100a+10b+c)^2=(a+b+c)^5 ...
Now, we know that, any three - Digit Number can be written in the form of (100a + 10b + c).
So, we can say that, we have To Find a Three - Digit Number , if we Square the Number , we will get, (sum of digits )^5.
with This we can conclude 2 Things :-
⓵ (100)² ≤ (a+b+c)^5 ≤ (999)² [ As Highest Three digit Number is 999].
❷ (a + b + c) must be a Square ..
with 2nd conclusion we can say that, (a + b + c) can be :- 1 , 4 , 9 , 16 and 25 .
Now, By Inequality we can say that, (a + b + c) can be 1 , 4 or 9.
But, with 1st Conclusion { (100)² ≤ (a + b+c)², we can conclude That, (1)^5 and (4)^5 are very Small..
So, We conclude that (a + b + c) = 9.
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Putting This value in Given now :-
➪ (100a+10b+c)²=(a+b+c)^5
➪ (abc)² = (9)^5 { Here, abc = A three - digit Number .}
Square - Root both sides ,
➪ abc = √(9^5)
➪ abc = √((3)²)^5
➪ abc = √(3)^10
➪ abc = √(3^5)²
Now, we know that , √(a)² = a .
➪ abc = 3^5
➪ abc = 3 * 3 * 3 * 3 * 3
➪ abc = 243 .
Hence, our Three Digit Number is 243, where a = 2, b = 4 and c = 3.
___________________________
So,
☞ (a² + b² + c²)
☞ (2² + 4² + 3²)
☞ (4 + 16 + 9)
☙ ☛ 29 (Ans). ☘
Step-by-step explanation:
Let N = ( 100a+10b+c)² = (a+b+c)^5
For Prime 'P' and positive integer 'n'
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Let ep(n) denote the highest power of 'P' dividing 'n'
Since 'N' is both a square and a fifth power ep(n) is divisible by both 2 & 5 and hence by 10 for each prime 'p' dividing 'N' .
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Thus,
N=
and So 100a+10b+c = m^5
While a+b+c= m²
Now,
2^5 < 111 ≤ 100a + 10b+ c ≤ 999 < 3^5
100a + 10b+ c = 3^5 = 243
From above we verify that,
(243)² = (3^5)² = (3²)^5 = (2+4+3)^5
So, Therefore a=2, b= 4, c=3
Now putting the values of a , b and c in equation (a²+b²+c²)