SOLUTION: Dear tutor, I have attempted 2 calculating processes for a determinant question, here I say Process 1 and Process 2. The original question is: |2 1 1| |1 -1 1| |3 -2 3|

Question 978749: Dear tutor,
I have attempted 2 calculating processes for a determinant question, here I say Process 1 and Process 2.
The original question is:
|2 1 1|
|1 -1 1|
|3 -2 3|
Process 1
|2 1 1| | 0 0 1|
|1 -1 1|=|-1 -2 1|=1|-1 -2|=1(5-6)=-1
|3 -2 3| |-3 -5 3| |-3 -5|
Process 2
|2 1 1| |2 1 1| |2 1 1| |3 5 0|
|1 -1 1|=|1 -1 1|=|1 2 0|=|1 2 0|=1|3 5|=1(6-5)=1
|3 -2 3| |5 6 1| |5 6 1| |5 6 1| |1 2|
I have checked with many determinant tools which shown that Process A's answer is correct but Process B's is wrong.
My question is I have checked both Processes(multiplication, addition or substraction)are correct BUT got different answers.
I am very confused what's wrong with Process B which have correct calculating process but got wrong answer.
I hope my tutor can explained DETAILEDLY what's going wrong with calculation in Process B for I will attend Precalculus examination later.
I should show my kindly appreciation in advance.
Answer by Alan3354(69443) (Show Source): You can put this solution on YOUR website!
The original question is:
|2 1 1|
|1 -1 1|
|3 -2 3|
================
That's 3 by 3 matrix, not a question.
---
It's not clear what you show that you tried.
---
You didn't say what you're trying to do, but you probably want to find the determinant.
Using minors for the 1st row:
---------
Det = 2*(-3+2) - 1*(3-3) + 1*(-2+3)
= -2 - 0 + 1
= -1

RELATED QUESTIONS
Please help me on this beauty of an equation. I need to complete the ordered pairs so... (answered by stanbon)

Factor: w^2-49z^2 - another factoring question, I have tried and I just don't get the... (answered by ewatrrr)

I am looking for a non-profit tutor. I am having problems understanding the process of... (answered by Mathtut)

There is a question on the practice Compass test I don't understand. It is; For all... (answered by MathLover1)

IN a shipment of 40 stoves, 2 are defective. What percentage is defective? This seems... (answered by Alan3354,macston)

Dear Sir As a 72 year old, interested in numbers and algebra, but with very limited... (answered by aaaaaaaa)

Dear Math Tutor, Please help me with: The points A(1,2), B(3,5), C(6,6) and D form a... (answered by ewatrrr)

Dear Math Tutor, Please help me simplify: 5(square root of 2+1)- square root of 2(4-3 (answered by ben720)

5. (a) A production process comprises of two separate processes, moulding and assembly.... (answered by stanbon)