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Maths Puzzle
Find (a^2 + b^2) if
a^3 - b^3 + ab = 35^2
a^3 - b^3 - 3ab = 1
Where a,b are positive integers
Read Solution (Total 2)
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- Ans:) 613..
a^3 - b^3 + ab = 35^2
a^3 - b^3 - 3ab = 1
by solving these two equations we can get ab = 306
and a^3 - b^3 = 919
Identity 1:
a^3 - b^3 = (a-b)^3 +3ab(a-b)
lets assume (a-b) = x and we got a^3 - b^3 = 919 and ab = 306
den x^3 - 0.x^2 +3(306)(x) = 919
by solving the equation one root is 1
so a-b = 1
Identity 2:
a^3 - b^3 = (a-b)(a^2 + ab + b^2)
919 = (1)(a^2 + 306 + b^2)
919 - 306 = (a^2 + b^2)
therefore (a^3 - b^3) = 613...
enjoyyy.... - 12 years agoHelpfull: Yes(5) No(0)
- if a^3-b^3+ab=15^2
and a^3-b^3-3ab=1
then a=8 and b=7
and ans of a^2+b^2=113 - 12 years agoHelpfull: Yes(0) No(2)
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