I have th following matrix and I am suppose to determine whether the matrix is in row-echelon form(R-E), reduced row-echelon(R-RE) form, both, or neither.. I know the following about R-R-E * If there is a row of all 0's there at the bottom of the matrix * The upper left most number has to be a 1 * the following number below it has to be to the right of the leading 1 has to be a 1.. * in R-RE any number above the 1 and below have to be 0.. - For R-E they have to be only below the 1 not above it.. all right, So here is the matrix: 1 2 0 3 0 0 0 1 1 0 0 0 0 0 1 0 0 0 0 0 The book shows the answer as being both a R-R-E and R-E. I disagree because the 1 below the 3, if it were in R-R-E, that 3 would have to be a 0. Therefore, I believe it is in R-E form. Am I correct in my reasoning? thanks in advance..