Question

решите систему : (x-2)(y+1)=1,x-y=3

Answer 1

x-y=3 => x=3+y=> (x-2)(y+1)=(3+y-2)(y+1)=(1+y)(y+1)=y+1+y²+y=y²+2y+1
ответ:y²+2y+1