Question

solve this matrix for me? using row echelon form

1 2 1 3
2 1 1 16
1 1 2 9

Answer 1

is it ok if i use my phone? theres an app for this >.> lolol

Answer 2

i know the answer but just dont know how to do it

Answer 3

i got this far
1 2 1 3
0 1 -5 -14
0 0 -4 -8

Answer 4

if thats even right

Answer 5

1 2 1 3
2 1 1 16
1 1 2 9 times last row by -2 then add to row above

1 2 1 3
0 -1 -3 -2 add 2nd row to last
1 1 2 9

1 2 1 3
0 -1 -3 -2
1 0 -1 7 multiply last row by -1 then add to first row


0 2 2 -4
0 -1 -3 -2
1 0 -1 7 switch row 1 with row 3


1 0 -1 7
0 -1 -3 -2
0 2 2 -4 divide last row by 2


1 0 -1 7
0 -1 -3 -2 add row 2 to row 3
0 1 1 -2

1 0 -1 7
0 -1 -3 -2 multiply row 2 by -1
0 0 -2 -4


1 0 -1 7
0 1 3 2
0 0 -2 -4 divide row 3 by -2


1 0 -1 7
0 1 3 2
0 0 1 2 add row 3 to row 1



1 0 0 9
0 1 3 2
0 0 1 2 multiply row 3 by -3 then add to row 2


1 0 0 9
0 1 0 -4
0 0 1 2


is that right?

Answer 6

and i guess since you didn't say reduced echelon form we could have left it in the form 2 steps before the reduced echelon matrix i have above

Answer 7

yea thats perfectly done! is there any tricks to doing these? or its just trial and error?

Answer 8

i showed you all my tricks

Answer 9

Lol thanks! you been helping me all day and i really appreciated!