SOLUTION: How many integer solutions(a,b,c) make the equation a^2+b^2+c^2=121 true

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Question 1186694: How many integer solutions(a,b,c) make the equation a^2+b^2+c^2=121 true
Answer by ikleyn(52776) About Me  (Show Source):
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How many integer solutions(a,b,c) make the equation a^2+b^2+c^2=121 true
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The basic solutions are these 3 triples:

a       b       c
-------------------

0       0       11     (1)

2       6        9     (2)

6	6	 7     (3)



1)  Triple (1) creates  3 permutations, that are the solutions, too.

                               Playing with the signs, each of these permutations provides  2 triples, that are the solutions, too.

    So, triple (1) produces 2*3 = 6 triples that are the solutions.



2)  Triple (2) creates  6 permutations, that are the solutions, too.

                               Playing with the signs, we get 6%2A2%5E3 = 6*8 = 48 triples, that are the solutions, too.

    So, triple (2) produces 48 triples that are the solutions.



3)  Triple (3) creates  3 distinguishable permutations, that are the solutions, too.

                               Playing with the signs, each of these 3 distinguishable permutations provides 8 triples, that are the solutions, too.

    So, triple (3) produces 3%2A2%5E3 = 24 triples that are the solutions.



In all,  there are   6 + 48 + 24 = 78   different integer triples that are the solutions.      ANSWER

Solved and explained.