Hello heonybaby
I would kindly ask you to be more specific in naming the posts and asking questions. Thus, "I have a question" is not preferable and should be avoided. From your post I did not quite understand what actually did you want to ask. I guess that you wanted to ask how to solve the system of algebraic equations.
1. If the system is linear like yours, here you are:
[MATH=eng]A←mat(0,8,2,3,5,2,6,2,8,3,3)[/MATH] [MATH=eng]d←mat(-7,8,26,3,1)[/MATH]
[MATH=eng]x←A^{-1}*d[/MATH] [MATH=eng]x=mat(4,-1,0.5,3,1)[/MATH]
2. If the system is nonlinear try "roots" function
[MATH=eng]x.guess←mat(1,1,1,3,1)[/MATH] [MATH=eng]X←mat(el(X,1),el(X,2),el(X,3),3,1)[/MATH]
[MATH=eng]z←roots(A*X-d,X,x.guess)[/MATH]
[MATH=eng]z=mat(4,-1,0.5,3,1)[/MATH]
Regards,
Radovan
When Sisyphus climbed to the top of a hill, they said: "Wrong boulder!"