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:
A←mat(0,8,2,3,5,2,6,2,8,3,3) d←mat(-7,8,26,3,1)
x←A^{-1}*d x=mat(4,-1,0.5,3,1)

2. If the system is nonlinear try "roots" function
x.guess←mat(1,1,1,3,1) X←mat(el(X,1),el(X,2),el(X,3),3,1)
z←roots(A*X-d,X,x.guess)
z=mat(4,-1,0.5,3,1)

Regards,
Radovan