For what values of k is the system of equations kx + 3y = k - 2, 12x + ky = k inconsistent?


Given: kx + 3y = k - 2,


 


12x + ky = k


 


We know that the general form for a pair of linear equations in 2 variables x and y is a1x + b1y + c1 = 0


 


and a2x + b2y + c2 = 0.


 


Comparing with above equations,


 


we have a1 = k, b1 = 3, c1 = - (k – 2); a2 = 12, b2 = k, c2 = - k


 



 



 



 


For given equations to be inconsistent,


 



 



 


By cross multiplication, k2 = 36


 


So, k = ±6


 


For k = ±6, the system of equations kx + 3y = k - 2, 12x + ky = k is inconsistent.


 

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