Find a solution: $3(x^2+y^2+z^2)=10(xy+yz+zx)$
As far as I understand - this is the site for solving the problem. Programming and calculation using the computer is not mathematics. If you want to calculate - there is a special section. https://mathematica.stackexchange.com/questions
Here it is necessary to solve the equations.
For the equation:
$$3(x^2+y^2+z^2)=10(xy+xz+yz)$$
The solution is simple.
$$x=4ps$$
$$y=3p^2-10ps+7s^2$$
$$z=p^2-10ps+21s^2$$
$p,s - $ any integer which we ask.
Why make a program? What's the point? For what?
This was a bunch of nonsense characters typed by hand so that the software would not test me with a ``captcha''
0 1 3
0 3 1
1 0 3
1 3 0
3 0 1
3 1 0
3 9 40
3 40 9
5 32 119
5 119 32
8 11 65
8 65 11
9 3 40
9 40 3
11 8 65
11 65 8
13 15 96
13 96 15
15 13 96
15 96 13
32 5 119
32 119 5
40 3 9
40 9 3
65 8 11
65 11 8
96 13 15
96 15 13
119 5 32
119 32 5
When he wrote the equation he meant probably that entry.
$$q(x^2+y^2+z^2)=(3q+1)(xy+xz+yz)$$
It turns out, this equation has a connection with the Pell equation:
$$p^2-5s^2=\pm1$$
For $+1$ it is necessary to use the first solution $(9 ; 4)$. For $-1$ it is necessary to use the first solution $(2 ; 1)$. Knowing what the decision can be found on the following formula.
$$p_2=9p_1+20s_1$$
$$s_2=4p_1+9s_1$$
Using the solutions of the Pell equation can be found when there are solutions. $q=\mp(p^2-s^2)$
Will make a replacement. $t=\mp4ps$ Then the solution can be written:
$$x=2(q+1)tkn$$
$$y=(q+t+1)k^2-2(3q+1)tkn+(t-q-1)(10q^2+7q+1)n^2$$
$$z=(t-q-1)k^2-2(3q+1)tkn+(t+q+1)(10q^2+7q+1)n^2$$
$k,n $ - integers asked us. May be necessary, after all the calculations is to obtain a relatively simple solution, divided by the common divisor.