Matrices multiple-choice question. Half an hour later... still can't work it out.
If A = | 1 4 1 | and X = | p | and AX = | b | then,
| 2 -3 0 | | q | | 2a |
| 1 0 0 | | r | | a |
A. r = b - a
B. r = a - b
C. r = -1
D. r = 1
E. r = a + b
The way I would go about the question is by using the simultaneous equation's techniques in matrices. Since u haven't actually said which is the answer I'm not sure if the way I did it is correct.
Firstly , my answer was option a, so if that's not the answer disregard my explanation.
So what I did is I acted as if my unknown were in matrix x (which it is ) , so the question itself does A*X=AX , to find X I did the inverse of A multiplied by the product matrix AX, so A
-1*AX , this would give u the value of X .
Input in calculator and answer is the third value in the 3*1 matrix , which for me was b-1a which is equivalent to b-a ,meaning that the answer is a
I hope that helps.
As I said , if my answer was incorrect plz disregard it , and tell me so we can figure out how to actually do the question.