SOLUTION: Please help me solve this. Find the value of k such that the system of linear equations is inconsistent. 4x + 2y = 6 −6x + ky = −8

Algebra ->  Coordinate Systems and Linear Equations -> SOLUTION: Please help me solve this. Find the value of k such that the system of linear equations is inconsistent. 4x + 2y = 6 −6x + ky = −8       Log On


   

Question 353734: Please help me solve this. Find the value of k such that the system of linear equations is inconsistent.
4x + 2y = 6
−6x + ky = −8

Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
You can form the augmented matrix for this system, reduce it to echelon form, and find out that k should be equal to -3.
Done by your usual substitution method, the first equation leads to y+=+3-2x. Put into the 2nd equation, we get-6x%2Bk%2A%283-2x%29=8.
-6x%2B3k-2kx+=+8.
-%282k%2B6%29x+=+6-3k,
x+=+-%286-3k%29%2F%282k%2B6%29.
the denominator will be undefined if 2k%2B6=0, or k+=+-3.