Why they stack the vector that way

[transgalactic]

v1 is
(0)
(1)
(2)
(3)

v2 is
(2)
(a)
(1)
(0)

W1 is
(3)
(1)
(1)
(0)

W2 is
(-2)
(4)
(2)
(6)

i am asked to find the dim of v+w ??

i was told to flip each vector by 90 degrees
so
(a)
(b)
(c)
(d)

in the matrix presented a a row (a b c d)
and then do a row reduction

but they just keep it as it they were originaly (as columns) and do a row reduction

0 2 3 -2
1 a 1 4
2 1 1 2
3 0 0 6


??

 

[tiny-tim]

Hi transgalactic!

I'm not sure what your question is,

but if you're asking whether using a column reduction is just as valid as using a row reduction, the answer is yes.

 

[transgalactic]

no they present them as columns instead of flipping them
and then they do a row reduction

??

 

[HallsofIvy]

He answered your question: it doesn't matter whether you represent vectors as columns or rows!

 

[transgalactic]

ahhh ok
thanks :)

 

[transgalactic]

it does matter
because when i flipped it and did a row reduction i got
-2 4 2 6
0 10 8 6
0 0 -2-8a -6a+36
0 0 0 10a+40

but in the not flipped version i get
1 0 0 -2
0 1 0 4
0 0 1 2
0 0 0 -3a -3

??