Initialize a matrix $M$ to zeros of $5$ by $10.$

Modify the rows of M according to the following $($NOTE: you only need a single command for each row and should NOT type the elements explicitly$)$:

a$.$ Row$1$: A row vector that starts with $15$ with a constant spacing of $-3.$

b$.$ Row$2$: A row vector starting with $10$ and ends with $73.$

c$.$ Row$3$: The $7^{th}$ through $9^{th}$ elements are changed to $321.$

d$.$ Row$4$: All entries are the number $10.$

e$.$ Row$5$: A row vector of $12,6,0,-6,-12,12,18,24,30,36$