[질문] x²+y²+1+2(xy+x+y) 인수분해하면 뭔가요?

->x²+2xy+y²+1+2x+2y고,x²+y²+2xy=(x+y)²,즉(x+y)²+2(x+y)+1가되고x+y를A로치환하면A²+2A+1로또완전제곱식형태가됨.즉(A+1)²가답이므로원래값으로바꾸면(x+y+1)²