SOLUTION: x+y=11 Use Cramer's rule to solve the x-y=5 following system of equations. If D=0, use another method to solve the system.

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To solve the system of equations by Cramer's rule:




D is the matrix of coefficients as they appear
on the left of the equal sign:

D =  = 

Dx is the matrix which is like D except that,
   since x is the FIRST unknown letter, it has
   its FIRST column  replaced 
   by the column of numbers on the right side of
   the equal signs in the original system, .
   So

Dx =  = 

==================================================================

Dy is the matrix which is like D except that,
   since y is the SECOND unknown letter, it has
   its SECOND column  replaced 
   by the column of numbers on the right side of
   the equal signs in the original system, .
   So

Dy =  = 

=============================================================

Then x =  and y = 

=============================================================

 So for your system:

x + y = 11 
x - y =  5

Write that as 




D is the matrix of coefficients as they appear
on the left of the equal sign:

D =  =  =  = 

==================================================

Dx is the matrix which is like D except that,
   since x is the FIRST unknown letter, it has
   its FIRST column  replaced 
   by the column of numbers on the right side of
   the equal signs in the original system, .
   So

Dx =  =  =  = 

==================================================

Dy is the matrix which is like D except that,
   since y is the SECOND unknown letter, it has
   its SECOND column  replaced 
   by the column of numbers on the right side of
   the equal signs in the original system, .
   So

Dy =  =  =  = 

====================================================

Then x =  =  =  and y =  =  = .   

====================================================

Edwin