SOLUTION: when a question asks you to show something algebraically, DO NOT substitute numbers for the variables and give me an example. On the other hand, when a question asks you to show s

Question 30539: when a question asks you to show something algebraically, DO NOT substitute numbers for the variables and give me an example. On the other hand, when a question asks you to show something numerically or to provide an example, you may substitute numbers for the variables. Show all work.
Solve for the column vector v=[x] in the following matrix equation given that :
[y] (Please note that the v has a curved arrow above it)
A=[2 1]
[1 -3]
Av=[4]
[-5] (please note that the v has a curved arrow above it)

Answer by venugopalramana(3286) (Show Source):
You can put this solution on YOUR website!
Solve for the column vector v=[x] in the following matrix equation given that :
[y] (Please note that the v has a curved arrow above it)
A=[2 1]
[1 -3]
Av=[4]
[-5] (please note that the v has a curved arrow
HOPE YOU MEAN (A)*(V)=(AV) AND GIVEN (A) AND (AV) YOU WANT TO KNOW (V)..ASSUMING THAT WE HAVE
*=
SO WE GET
2X+Y=4...........I
X-3Y=-5............II
EQN.1- 2*EQN.II GIVES
2X+Y-2X+6Y=4+10=14
7Y = 14...Y = 2
X=-5+3Y=-5+3*2=1...HENCE
V=