diff --git a/matrix.c b/matrix.c
index c523d59..8b7a78f 100644
--- a/matrix.c
+++ b/matrix.c
@@ -132,7 +132,7 @@ Matrix add(const Matrix matrix1, const Matrix matrix2)
     */
 Matrix multiply(const Matrix matrix1, const Matrix matrix2)
 {
-    if(matrix1.cols == matrix2.rows)
+    if(matrix1.cols == matrix2.rows && matrix1.buffer != NULL && matrix2.buffer != NULL)
     {
       Matrix mult = createMatrix(matrix1.rows, matrix2.cols);
       for(int i = 0; i < matrix1.rows; i++)
@@ -140,11 +140,12 @@ Matrix multiply(const Matrix matrix1, const Matrix matrix2)
         for(int j = 0; j < matrix2.cols; j++)
         {
           MatrixType wert = 0;
+          MatrixType res = 0;
           for(int k = 0; k < matrix2.rows; k++)
           {
             wert = getMatrixAt(matrix1, i, k) * getMatrixAt(matrix2, k, j);
-            MatrixType res = wert;
-            wert = res + wert;
+            res = res + wert;
+            wert = res;
           }
           setMatrixAt(wert, mult, i, j);
         }
@@ -160,103 +161,3 @@ Matrix multiply(const Matrix matrix1, const Matrix matrix2)
 
 
 
-/* MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int colIdx)
-{
-    if (matrix.buffer == NULL || rowIdx >= matrix.rows || colIdx >= matrix.cols)
-    {
-        return UNDEFINED_MATRIX_VALUE;
-    }
-
-    return matrix.buffer[rowIdx * matrix.cols + colIdx];
-}
-
-Matrix add(const Matrix matrix1, const Matrix matrix2)
-{
-    Matrix result;
-
-    if (matrix1.buffer == NULL || matrix2.buffer == NULL || matrix1.rows != matrix2.rows)
-    {
-        result.rows = 0;
-        result.cols = 0;
-        result.buffer = NULL;
-        return result;
-    }
-
-    if (matrix1.cols == matrix2.cols)
-    {
-        result = createMatrix(matrix1.rows, matrix1.cols);
-        for (int i = 0; i < matrix1.rows; i++)
-        {
-            for (int j = 0; j < matrix1.cols; j++)
-            {
-                MatrixType value = getMatrixAt(matrix1, i, j) + getMatrixAt(matrix2, i, j);
-                setMatrixAt(value, result, i, j);
-            }
-        }
-        return result;
-    }
-
-    if (matrix1.cols == 1 && matrix2.cols > 1)
-    {
-        result = createMatrix(matrix1.rows, matrix2.cols);
-        for (int i = 0; i < matrix1.rows; i++)
-        {
-            for (int j = 0; j < matrix2.cols; j++)
-            {
-                MatrixType value = getMatrixAt(matrix1, i, 0) + getMatrixAt(matrix2, i, j);
-                setMatrixAt(value, result, i, j);
-            }
-        }
-        return result;
-    }
-    else if (matrix2.cols == 1 && matrix1.cols > 1)
-    {
-        result = createMatrix(matrix1.rows, matrix1.cols);
-        for (int i = 0; i < matrix1.rows; i++)
-        {
-            for (int j = 0; j < matrix1.cols; j++)
-            {
-                MatrixType value = getMatrixAt(matrix1, i, j) + getMatrixAt(matrix2, i, 0);
-                setMatrixAt(value, result, i, j);
-            }
-        }
-        return result;
-    }
-
-    //Fall: Unterschiedliche Spaltenanzahl, beide ungleich 1
-    result.rows = 0;
-    result.cols = 0;
-    result.buffer = NULL;
-    return result;
-}
-
-Matrix multiply(const Matrix matrix1, const Matrix matrix2)
-{
-    Matrix result;
-
-    if (matrix1.buffer == NULL || matrix2.buffer == NULL || matrix1.cols != matrix2.rows)
-    {
-        result.rows = 0;
-        result.cols = 0;
-        result.buffer = NULL;
-        return result;
-    }
-
-    result = createMatrix(matrix1.rows, matrix2.cols);
-
-    for (int i = 0; i < matrix1.rows; i++)
-    {
-        for (int j = 0; j < matrix2.cols; j++)
-        {
-            MatrixType sum = 0;
-
-            for (int k = 0; k < matrix1.cols; k++)
-            {
-                sum += getMatrixAt(matrix1, i, k) * getMatrixAt(matrix2, k, j);
-            }
-            setMatrixAt(sum, result, i, j);
-        }
-    }
-
-    return result;
-}*/
\ No newline at end of file