Question 578099
<pre>

{{{system(Px+Qy=R,Sx+Ty=U)}}}

is solved by calculating these three determinants:

{{{D}}} = {{{abs(matrix(2,2,P,Q,S,T))}}} = {{{PT-QS}}}

{{{D[x]}}} = {{{abs(matrix(2,2,R,Q,U,T))}}} = {{{RT-QU}}}

{{{D[y]}}} = {{{abs(matrix(2,2,P,R,S,U))}}} = {{{PU-RS}}}

Then

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

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

Your system

{{{system(3x+2y=13,2x-y=4)}}}

has P=3, Q=3, R=13, S=2, T=-1, U=4

Substitute those into the above and you will get:

x = 3, y = 2

Edwin</pre>