下列何者為(x-y)²-8(y-x)+12的因式? (A)x-y-2 (B)x+y-6 (C)x+y+6 (D)x-y+6?

(x - y)² - 8(y - x) + 12
= (x - y)² + 8(x - y) + 12
= [(x - y) + 2] [(x - y) + 6]
= (x - y + 2)(x - y + 6)

...... 答案選(D) x - y + 6

(x-y)²-8(y-x)+12
=(x-y)²+8(x-y)+12
=[(x-y)+2][(x-y)+6]
=(x-y+2)(x-y+6)
=D

D
先把x-y看成一個就可以了