Z^2+4z-4 factor the polynomial

thnx

X = -4+ Sqr root of 4^2 - 4*1* (-4) / 2*1
= -4 + sqr root of 16+4 / 2
= -4 + sqr root of 20 / 2
= -4 + 4 sqr root of 5 / 2
= 4 ( -1 + sqr root of 5 ) / 2
= 2 (-1 + sqr root of 5 )
Y = -4 - further same process

The expression does not factorise - check the question.