數學問題計10個unknows

這類問題係system of linear equation
如果你有學過Matrix
第二條其實可以寫成咁
　1　 1　　X　　　10
[　　　　] [　　] = [ 　　]
　2 　-1　　Y　　　 5
用Ax = b表示
要解決就計 x = A^-1 b
A^-1係A既inverse

係電腦裏面有好多方法可以解決到
例如Jacobi method, Gauss-Seidel method等等
但如果你唔識matrix即話，就會比較難明lu

可以參巧下
http://en.wikipedia.org/wiki/System_of_linear_equations
或者有個online solver
http://wims.unice.fr/wims/wims.cgi?module=tool/linear/linsolver.en

There are many math software available but all of them require you having the basic knowledge of "matrix" and "linear algebra" and "system of linear equations". You may try to search "Matlab" or "Mathematica". However, you should notice that the solution may not be unique even in the case n=2 "two eqn two known". e.g. 5x+y=4 and 10x+2y=8. You may say that this is obvious but this is usually not obvious if n>=3.

Yes, search for the calculator programs software