Question 1151145: There are two triples of positive integers (a,b,c and d,e,f) such that a^2+b^2+c^2 = 86 and d^2+e^2+f^2 = 86. Numbers should not repeat within each triplet. Evaluate the expression | abc-def |
Found 2 solutions by Edwin McCravy, ikleyn: Answer by Edwin McCravy(20059) (Show Source):
You can put this solution on YOUR website! There are two triples of positive integers (a,b,c and d,e,f) such that
a^2+b^2+c^2 = 86 and d^2+e^2+f^2 = 86. Numbers should not repeat within each
triplet. Evaluate the expression | abc-def |
We'll assume a < b < c and d < e < f
a,b,c,d,e,f all have to be 9 or less. The squares are
1,4,9,16,25,36,49,64,81
Three of these must have sum 86
We try c = 9
a² + b² + c² = 86
a² + b² + 9² = 86
a² + b² + 81 = 86
a² + b² = 5
We see that the first two, 1 and 4, have sum 5
so (a,b,c) or (d,e,f) can be (1,4,9)
We try c = 8
a² + b² + c² = 86
a² + b² + 8² = 86
a² + b² + 64 = 86
a² + b² = 22
No two of these 1,4,9,16,25,36,49,64,81 add to 22, so
we try c = 7
a² + b² + c² = 86
a² + b² + 7² = 86
a² + b² + 49 = 86
a² + b² = 37
We see that 1+36=37,
so (a,b,c) or (d,e,f) can be (1,6,7)
Let's let (a,b,c) = (1,4,9) and (d,e,f) = (1,6,7)
You calculate | abc-def |
Edwin
Answer by ikleyn(52800) (Show Source):
You can put this solution on YOUR website! .
1) 86 = 1^2 + 2^2 + 9^2
2) 86 = 1^2 + 6^2 + 7^2.
So, a= 1, b= 2, c= 9; d= 1, e= 6, f= 7.
abc = 18, def = 42, | abc - def | = 42 - 18 = 24. ANSWER
Solved.
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