The matrix is .
Since a12 is the element in row 1, column 2.
Observe the matrix A; it has 3 rows and 2 columns.
Since a12 is the element in row 1, column 2 the value of a12 = y.
The matrix a12 element is y.
![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
![\"\"](\"/test/fckeditor/editor/plugins/fckeditor_wiris/integration/showimage.php?formula=0b26227341dec8c86924ee10cf4c8d15.png\")
.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")