(x-y)^2+7(x+y)-11(x-y)^2-8(x+y),先化简.再求值_数学解答

(x-y)^2+7(x+y)-11(x-y)^2-8(x+y),先化简.再求值

人气：382 ℃　时间：2020-06-11 00:59:46

解答

(x-y)^2+7(x+y)-11(x-y)^2-8(x+y),
=-10(x-y)²-(x+y) 当x+y=-3,x-y=-1时
=-10*(-1)²-(-3)
=-10+3
=-7