Let two positive intigers be such that their sum is 9 and the sum of their fourth powers is 2417. Find the two numbers?
@Arnab09 @yash2651995
\( \color{Black}{\Rightarrow a + b = 9 }\) \( \color{Black}{\Rightarrow a^4 + b^4 = 2417 }\) Although you may attempt a trial and error here.
this doesnt seem easy lol
8,1 ; 7,2 ; 3,6 ; 4,5
Check if any of em satisfy the second equation.
saw one :D
Yes... I got it ;D
Go put these in your calculator. \( \color{Black}{\Rightarrow 8^4 + 1^4 }\) \( \color{Black}{\Rightarrow 7^4 + 2^4 }\) \( \color{Black}{\Rightarrow 6^4 + 3^4 }\) \( \color{Black}{\Rightarrow 5^4 + 4^4 }\)
\[(a+b)^{4}= a ^{4}+b ^{4}+4(ab)(a+b)+6(ab)^{2}\] find (ab) from here .. then put it in \[(a-b)^{2}=(a+b)^{2}-4(ab)\] then find a-b use a+b=9 and a-b= ..what ever you get.. to find a and b
ab will be positive..^
your formulla is wrong @yash2651995 please recheck
ya.. let me correct it..
formulla is (a+b)^4 = a^4 + 4a^3 b + 6a^2 b^2 + 4ab^3 + b^4 => a^4 + b^4 + ab ( 4a^2 + 4b^2 + 6ab)
and a^2+ b^2 = 81 -2ab now you can make this subsn and this should just do it
\[(a+b)^{4}=a ^{4}+b ^{4}+4ab(a+b)^{2}-2(ab)^{2}\]
yep..same thing
ab=14 or 148..
a-b=5
a=7 b=2
or a=2 b=7
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