Question

分解因式(xy-1)的平方+(x+y-2)(x+y-2xy)

Answer 1

(xy-1)^2+(x+y-2xy)(x+y-2)

=(xy-1)^2+4xy+(x+y)^2-2(xy+1)(x+y)

=(xy+1)^2+(x+y)^2-2(xy+1)(x+y)

=(x+1)^2(y+1)^2