diff --git a/matrix.c b/matrix.c
index dab5873..bcdf3e8 100644
--- a/matrix.c
+++ b/matrix.c
@@ -52,25 +52,54 @@ MatrixType getMatrixAt(const Matrix matrix, unsigned int rowIdx, unsigned int co
 
 Matrix add(const Matrix matrix1, const Matrix matrix2)
 {
-    // test, if two matrix has exact size
-
-    if (matrix1.rows != matrix2.rows || matrix1.cols != matrix2.cols)
-        return createMatrix(0, 0);
-
-    Matrix result_add = createMatrix(matrix1.rows, matrix1.cols);
-
-    for (int r = 0; r < matrix1.rows; r++)
+    // check, equal rows
+    if (matrix1.rows == matrix2.rows)
     {
-        for (int c = 0; c < matrix1.cols; c++)
-        {
-            // TODO: matrix_add initialisieren
-            // matrix_add[r][c] = matrix1[r][c] + matrix2[r][c]
+        Matrix result_add = createMatrix(matrix1.rows, matrix1.cols);
 
-            MatrixType sum = getMatrixAt(matrix1, r, c) + getMatrixAt(matrix2, r, c);
-            setMatrixAt(sum, result_add, r, c); // evtl re
+        // "Elementweise Addition": test, if two matrix has exact size
+        if (matrix1.rows == matrix2.rows && matrix1.cols == matrix2.cols)
+        {
+            for (int r = 0; r < matrix1.rows; r++)
+            {
+                for (int c = 0; c < matrix1.cols; c++)
+                {
+                    // first version: matrix_add[r][c] = matrix1[r][c] + matrix2[r][c]
+                    MatrixType sum = getMatrixAt(matrix1, r, c) + getMatrixAt(matrix2, r, c);
+                    setMatrixAt(sum, result_add, r, c);
+                }
+            }
         }
+        // "Broadcasting": matrix1 has 1 collum
+        else if (matrix1.cols == 1)
+        {
+            for (int r = 0; r < matrix1.rows; r++)
+            {
+                for (int c = 0; c < matrix2.cols; c++)
+                {
+                    MatrixType sum = getMatrixAt(matrix2, r, c) + getMatrixAt(matrix1, r, 0);
+                    setMatrixAt(sum, result_add, r, c);
+                }
+            }
+        }
+        // "Broadcasting": matrix2 has 1 collum
+        else if (matrix2.cols == 1)
+        {
+            for (int r = 0; r < matrix1.rows; r++)
+            {
+                for (int c = 0; c < matrix1.cols; c++)
+                {
+                    MatrixType sum = getMatrixAt(matrix1, r, c) + getMatrixAt(matrix2, r, 0);
+                    setMatrixAt(sum, result_add, r, c);
+                }
+            }
+        }
+
+        return result_add;
     }
-    return result_add;
+
+    else if (matrix1.rows == matrix2.rows && matrix1.cols == matrix2.cols)
+        return createMatrix(0, 0);
 }
 
 Matrix multiply(const Matrix matrix1, const Matrix matrix2)