Question 39273
{{{ matrix(2,2,
1,-4,
4,-1) }}}


D = (-1) - (-16)
D = -1+16
D = 15


Now, Dx = {{{ matrix(2,2,
4,-4,
1,-1) }}}


Dx = (-4) - (-4)
Dx = -4 + 4
Dx = 0


and Dy = {{{ matrix(2,2,
1,4,
4,1) }}}


Dy = 1 - 16
Dy = -15


So, x = Dx/D
x = 0/15
x = 0


and y = Dy/D
y = -15/15
y = -1


CHECK:
x-4y should be 4
0-4(-1)
4... correct


4x-y should be 1
0-(-1)
1... correct


jon.