# Am I missing any parameter's to get a solution

Posted 1 year ago
1687 Views
|
2 Replies
|
0 Total Likes
|
 I am trying to solve an equation that I know has solutions, but what I am trying isn't working as expected, am I missing something? Here is the equation Reduce[{160755614715009600 + 152 y^2 + 2630 z^2 == m (2567290440 + 152 y + 2630 z), y > 0, z > 0, m > 0}, {y, z, m}, Integers] Which gives me (y | z | m) \[Element] Integers && y >= 1 && z >= 1 && m == (80377807357504800 + 76 y^2 + 1315 z^2)/( 1283645220 + 76 y + 1315 z) Yet if I give the value for "m", I get a solution thus Reduce[{160755614715009600 + 152 y^2 + 2630 z^2 == 33395648 (2567290440 + 152 y + 2630 z), y > 0, z > 0}, {y, z}, Integers] Resulting in (y == 37928418 && z == 1194380) || (y == 37928418 && z == 32201268) || (y == 46962630 && z == 2087228) || (y == 46962630 && z == 31308420) Or am I expecting too much? Answer
2 Replies
Sort By:
Posted 1 year ago
 Hi Paul,Interesting that FindInstance gives this solution eq = 160755614715009600 + 152 y^2 + 2630 z^2 - m (2567290440 + 152 y + 2630 z) == 0 FindInstance[{eq, y > 0, z > 0, m > 0}, {m, y, z}, Integers] (* {{m -> 62616840, y -> 62616840, z -> 62616840}} *) eq /. {m -> 62616840, y -> 62616840, z -> 62616840} (* True *) Answer
Posted 1 year ago
 It's interesting that FindInstance only finds 1 solution, when there are many solutions, these are just the first few 62616840 , {{y->62616840,z->62616840}} 62616826 , {{y->131915080,z->10050766},{y->131915080,z->52566060}} 62616812 , {{y->92362065,z->2647718},{y->92362065,z->59969094}} 62616758 , {{y->122326338,z->7684682},{y->122326338,z->54932076}} 62616688 , {{y->25532718,z->63478756},{y->27384238,z->63494884},{y->35232450,z->63494884},{y->37083970,z->63478756},{y->96758670,z->3214116},{y->96758670,z->59402572}} Maybe its because there's too many solutions. Answer