SOLUTION: Hello. I have just started a new math class, and the teacher is very hard to understand. When someone asks him a question, he thinks they are making fun of his accent. I am trying

Question 70442: Hello. I have just started a new math class, and the teacher is very hard to understand. When someone asks him a question, he thinks they are making fun of his accent. I am trying to a few things out but cannot. He gives us sample problems and does not even go out of a book. The problem directions are Find
A-1 and check your answer. The problem is
A= (1 -2 3)
(-1 0 2)
(4 1 5)
Could someone show me the formula for this problem, and perhaps lead me through it? I am lost and do not want to drop this class. Thanks in advance.
Answer by venugopalramana(3286) (Show Source): You can put this solution on YOUR website!
Hello. I have just started a new math class, and the teacher is very hard to understand. When someone asks him a question, he thinks they are making fun of his accent. I am trying to a few things out but cannot. He gives us sample problems and does not even go out of a book. The problem directions are Find
A-1 and check your answer. The problem is
A= (1 -2 3)
(-1 0 2)
(4 1 5)
WHAT IS A? IS IT A MATRIX ..ASSUMING SO...
THEN IS IT A-1 OR A-I?...IF A IS A MATRIX , IT MAKES BETTER SENSE IF IT IS A-I
I IS UNIT MATRIX ..WE TAKE IT AS SAME ORDER AS A...THAT IS IT WILL 3 ROWS AND 3 COLUMNS..I=
1,0,0
0,1,0
0,0,1
THEN A-I =...SUBTRACT EACH ELEMENT OF I FROM ITS CORRESPONDING ELEMENT IN A
1-1,-2-0,3-0
-1-0,0-1,2-0
4-0,1-0,5-1
=
0,-2,3
-1,-1,2
4,1,4

Could someone show me the formula for this problem, and perhaps lead me through it? I am lost and do not want to drop this class. Thanks in advance.
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