[질문] x제곱-y제곱-z제곱+2yz+x+y-z 인수분해좀요

x^2-y^2-z^2+2yz+x+y-z=x^2+x-(y^2-2yz+z^2)+y-z=x^2+x-(y-z)^2+(y-z)=x^2+x-(y-z)(y-z+1)=(x-y+z)(x+y-z+1)