Question regarding reduced row

canadianicon25 · **Posted:** Fri, 28 May 2010 01:38:43 UTC

i have this matrix

3 -4 10
-5 8 -17
-3 12 -12

my first operation ( to put it into reduced row) is to simply divide the first row by three. why can't my second operation be to simply add 5 to the second row? the recommended operation is R2+5R1.

i don't understand why the first row can simply be divided by a number while the second operation must be interns of existing rows.

Soroban · **Posted:** Fri, 28 May 2010 11:44:43 UTC

Hello, canadianicon25!

Check your notes . . .

Quote:

i have this matrix: . $\left|\begin{array}{ccc} 3 & \text{-}4 & 10 \\ \text{-}5 & 8 & \text{-}17 \\ \text{-}3 & 12 & \text{-}12 \end{array}\right|$

My first operation (to put it into reduced row) is to simply divide the first row by three.
Why can't my second operation be to simply add 5 to the second row?
You can do anything you want . . . if you don't need the correct answer.

There are only two legal operations:

. . [1] Multiply a row by a nonzero constant (including fractions).

. . [2] Add a multiple of one row to another row.

S.O.S. Mathematics CyberBoard

Question regarding reduced row

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