Question 136141

You need to create three 2X2 matrices of the form


{{{(matrix(2,2,a,b,c,d))}}}  and the value of this matrix is: {{{ad-cb}}}


The first has the coefficients of the variables:


{{{D=(matrix(2,2,6,12,4,7))}}}.  Use the formula above to calculate the value of D


The second matrix is the same as the first with the 1st column replaced by constant values on the right side of your equations.


{{{D[x]=(matrix(2,2,33,12,20,7))}}}.  Use the formula above to calculate the value of {{{D[x]}}}


{{{D[y]}}} is the same process, but replace the 2nd column with the constant values.   Use the formula above to calculate the value of {{{D[y]}}}



Then Cramer's Rule says:


{{{x=D/D[x]}}}


{{{y=D/D[y]}}}


-- if the system is independent.  If {{{D}}},{{{D[x]}}}, or {{{D[y]}}} = 0, Cramer's Rule doesn't work.