SOLUTION: I am stuck on a project, and am desperate for help. My teacher denied me any help during class, so I'm kind of packed into a corner. 1. I have to write an augmented matrix using t

Algebra ->  Matrices-and-determiminant -> SOLUTION: I am stuck on a project, and am desperate for help. My teacher denied me any help during class, so I'm kind of packed into a corner. 1. I have to write an augmented matrix using t      Log On


   



Question 443287: I am stuck on a project, and am desperate for help. My teacher denied me any help during class, so I'm kind of packed into a corner.
1. I have to write an augmented matrix using this system : 2x=5y 3y+x=-11
2.After I find the augmented matrix, I have to find two matrices that multiply to a product of the augmented matrix.

Answer by Edwin McCravy(20056) About Me  (Show Source):
You can put this solution on YOUR website!
I am stuck on a project, and am desperate for help. My teacher denied me any help during class, so I'm kind of packed into a corner.
1. I have to write an augmented matrix using this system : 2x=5y 3y+x=-11
2.After I find the augmented matrix, I have to find two matrices that multiply to a product of the augmented matrix.


system%282x=5y%2C3y%2Bx=-11%29

Get the equations in general form:

system%282x-5y=0%2C1x%2B3y=-11%29

The augmented matrix is just an array of all the numbers
in the system without the letters or equal signs:


%28matrix%282%2C3%2C%0D%0A%0D%0A+2%2C-5%2C0%2C%0D%0A+1%2C+3%2C-11%29%29

That's a 2x3 matrix.

To find two matrices that have a 2x3 matrix as their
product, the first could be a 2x2 and the second a 2x3
matrix. 

Let's make up an arbitrary 2x2 matrix, say

%28matrix%282%2C2%2C2%2C3%2C1%2C-4%29%29

Then we'll let the 2x3 matrix be:

%28matrix%282%2C3%2Cp%2Cq%2Cr%2Cs%2Ct%2Cu%29%29

So we have



Equating elements of the two 2x3 matrices:, we have 
these 3 systems of equations:

system%282p%2B3s=2%2Cp-4s=1%29, system%282q%2B3t=-5%2Cq-4t=3%29, system%282r%2B3u=0%2Cr-4u=-11%29, 

We solve those 3 systems and get p=1,s=0, q=-1,t=-1,r=-3,u=2

So one possible answer is




  
But you could make up any (non-singular) 2x2 matrix
and find a 2x3 matrix so that the product would be
equal to the augmented matrix.  There are many possible
answers, in fact infinitely many.

Edwin