Hi, if anyone could explain how you get from

(x+y+z+t)det 1 1 1 1

qqqqqqqqqqq y z t x

qqqqqqqqqqq z t x y

qqqqqqqqqqq t x y z

to

(x+y+z+t)det 0 1 1 1

qqqqqqqqqq (y-z+t-x) z t x

qqqqqqqqqq (z-t+x-y) t x y

qqqqqqqqqq (t-x+y-z) x y z

that would be brilliant! Totally confused

PS. The qs are just in there to make the matrices slightly more lined up (spaces don't seem to work)! Ignore the qs