내수입보기 | 수익출금 | 회원순위
① (2x-1)(-3x+4)= -6x 2 +11x-4
② (x+y-1)(x-y+1)=x 2 - y 2 +2y-1
③ (2x-3) 3 = 8x 3 - 36x 2 + 54x - 27
④ (x+1)(x 2 - x+1)= x 3 +1
⑤ (x+y-z) 2 = x 2 + y 2 - z 2 + 2xy - 2yz - 2zx