Let A=[1 1 2 3(1st … - QuestionCove
OpenStudy (anonymous):

Let A=[1 1 2 3(1st row), 1 2 3 4(2nd row), 1 2 4 5(3rd row)] and let B be the row-reduced echelon form of A. How many non-zero entries are there in the fourth column of matrix B?

3 years ago