Question

(a-b)(x-y)-(b-a)(x y)如何解题

Answer 1

如果题是：(a-b)(x-y)-(b-a)(x-y),则,

原式=(a-b)(x-y)+(a-b)(x-y)=2(a-b)(x-y).

如果题是：(a-b)(x-y)-(b-a)(x+y),则,

原式=(a-b)(x-y)+(a-b)(x+y)=(a-b)(x-y+x+y)=2x(a-b).