Question 39449
M = {{{ matrix(2,2,
2,-5,
-1,3
) }}}


Its determinant, D is:
D = (2)(3)-(-1)(-5)
D = 6-5
D = 1


Now repeat on
{{{ matrix(2,2,
18,-5,
10,3
) }}}


Dx = (18)(3)-(10)(-5)
Dx = 54+50
Dx = 104


and also on
{{{ matrix(2,2,
2,18,
-1,10
) }}}


Dy = (2)(10)-(-1)(18)
Dy = 20+18
Dy = 38


So, x = Dx/D
--> x = 104/1
--> x = 104


So, y = Dy/D
--> y = 38/1
--> y = 38


CHECK:
2x-5y
2(104)-5(38)
208-190
18... CORRECT


and -x+3y
-(104)+3(38)
-104+114
10... CORRECT


jon.