Question 1081779
Your matrix:
{{{matrix(4,5,1,1,1,-1,2,2,-1,1,5,9,3,1,1,-2,1,2,2,4,6,2)}}}

Write down the main matrix and find its determinant

{{{matrix(4,4,1,1,1,-1,2,-1,1,5, 3,1,1,-2,2,2,4,6)}}}

{{{D = 10}}}

Replace the 1st column of the main matrix with the solution vector and find its determinant:

{{{matrix(4,4,2,1,1,-1,9,-1,1,5,1,1,1,-2,2,2,4,6)}}}

{{{D[1] = -34}}}

Replace the 2nd column of the main matrix with the solution vector and find its determinant:

{{{matrix(4,4,1,2,1,-1,2,9,1,5,3,1,1,-2,2,2,4,6)}}}


{{{D[2] = -226}}}


Replace the 3rd column of the main matrix with the solution vector and find its determinant:

{{{matrix(4,4, 1,1,2,-1,2,-1,9,5,3,1,1,-2,2,2,2,6)}}}


{{{D[3] = 222}}}


Replace the 4th column of the main matrix with the solution vector and find its determinant:

{{{matrix(4,4, 1,1,1,2,2,-1,1,9,3,1,1,1,2,2,4,2)}}}

{{{D[4] = -58}}}


{{{x[1] = D[1] / D = (-34) / 10 = -17/5}}}

{{{x[2 ]= D[2] / D = (-226) / 10 = -113/5}}}

{{{x[3] = D[3] / D = 222 / 10 = 111/5}}}

{{{x[4] = D[4] / D = (-58) / 10 = -29/5}}}