SOLUTION: Solve the Following System of equations by using the inverse of the coefficent (AX=B) x+5y=25 5x+5y=45 The Inverse of matrix A, A-1 is? and what is the solution in ordered pair

Algebra ->  Matrices-and-determiminant -> SOLUTION: Solve the Following System of equations by using the inverse of the coefficent (AX=B) x+5y=25 5x+5y=45 The Inverse of matrix A, A-1 is? and what is the solution in ordered pair      Log On


   

Question 632358: Solve the Following System of equations by using the inverse of the coefficent
(AX=B) x+5y=25 5x+5y=45 The Inverse of matrix A, A-1 is?
and what is the solution in ordered pair please just post the answers i need in the box and the soultion for the system here is screenshot of question
http://oi47.tinypic.com/2cpx6l0.jpg
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi,

Solve the system of equations by using the inverse of the coefficient matrix.

 x+5y = 25 

5x+5y = 45

A+=+%28matrix%282%2C2%2Ca1%2Cb1%2Ca2%2Cb2%29%29+=+a1b2-b1a2                                  

A+=%28+matrix%282%2C2%2C1%2C5%2C5%2C5%29%29 = -20

A%5E%28-1%29+=+%281%2F%28a1b2+-+b1a2%29%29%28matrix%282%2C2%2Cb2%2C-b1%2C-a2%2Ca1%29%29





and...





Checking our answer using the Elimination Method:

 x+5y = 25 

5x+5y = 45   |Subtracting 1st EQ from the 2nd

  4x = 20  

   x = 5  and y = 4  as 5%2B5%2A4+=+25

(x,y) Ordered pair (5,4) the solution for this system of equations