u2+u-4u-4+(u2-u+1)(u+1)=u2+u-4u-4+u3+u2-u2-u+u+1=u2 - 5u - 3
u²+u-4u-4+(u²-u+1)(u+1)=u²-3u-4+u³+u²-u²-u+u+1=u²-3+u³
u2+u-4u-4+(u2-u+1)(u+1)=u2+u-4u-4+u3+u2-u2-u+u+1=u2 - 5u - 3
u²+u-4u-4+(u²-u+1)(u+1)=u²-3u-4+u³+u²-u²-u+u+1=u²-3+u³