Hey!

Does in general case, If i have (m x n) matrix A with full row rank rk(A)=m and add one more row (1,..,1) I get matrix A* with rk(A*)=m+1?

It does not seems true to me as one of the A rows can be k*(1,..,1), where k is real and then rk(A*) is not m+1. But I am asked to confirm that.