6. (4 pts) If A is an array of size N X M (where N and M are not given), write one line of MATLAB code to replace all elements in the first row of A with the value 1. 7. (4 pts) If A is an array of size N x M (where N and M are not given), write one line of MATLAB code to replace all elements in the odd rows of A with the value 1. 8. (5 pts) If A is an array of size NXM (where N and M are not given, but now we know that N is an even number), write one line of MATLAB code to replace the odd rows of A with the even rows of A, i.e., to replace row 1 with row 2, row 3 with row 4, etc