Question

(x+2y)(x-y)-(x+y)的二次方等于多少

Answer 1

（x+2y)(x-y)-(x+y)²
= x² -xy +2xy -2y² - x²-y²-2xy
=-3y²

秋风燕燕为您答题 O(∩_∩)O
有什么不明白可以对该题继续追问
如果满意，请及时选为满意答案，谢谢

Answer 2

（x+2y)(x-y)-(x+y)²
= x² -xy +2xy -2y² - x²-y²-2xy
=-3y²-xy
=-y(3y+x)
楼上太粗心了 采纳哦