# Tag Info

### Solving a system of linear equations modulo n

We now have LinearSolveMod in the Wolfram Function Repository ...

### Solving three equations with two unknowns with constant parameters

You can use Reduce or the following: ...
• 238k

### Non-valid modulus when using LinearSolve

We now have LinearSolveMod in the Wolfram Function Repository Get a solution and generating set for the null vectors: ...
• 59.3k
Accepted

### Find the diagonalizing matrix for a general 2*2 real valued symmetric matrix

Since the size of this matrix is 2x2, some elementary facts from linear algebra will help you a lot. I assume the matrix is real. Since it is symmetric, its eigenvalues, mm and mp, are real. Let me ...
• 916

...
• 160k
1 vote

### Finding kernel of a set of polynomial functions

Since your question lacks concrete example, I cannot judge my answer is really effective or not, but the following heuristics is very often useful. Consider the cases where variables x1,x2,x3, ... ...
• 916
1 vote

### Selecting terms containing some expression

expr = a*k + (a^2)*b*c + b*e; DeleteCases[expr, x_ /; MemberQ[x, e]] a^2 b c + a k First @ Cases[expr, x_ /; MemberQ[x, e]] ...
• 78.4k

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