Question

化简求值：(x的平方+y的平方)(x的平方-y的平方)-(x+y)的平方(x-y)的平方， 其中x=4y=1

Answer 1

解：(x²+y²)(x²-y²)-(x+y)²(x-y)²
=(x²+y²)(x²-y²)-(x²-y²)²
=(x²-y²)(x²+y²-x²+y²)
=(x²-y²)*(2y²)
=2x²y²-2y^4
当x=4,y=1时原式=2*16*1-2*1=32-2=30
希望你采纳！！！

Answer 2

(x2+y2)(x2-y2)-(x+y)2*(x-y)2
=x4-y4-(x2-y2)2
=x4-y4-(x4+y4-2x2y2)
=2x2y2=2X1X1X1/4X1/4
=1/8

注：跟在字母后面的数字为平方！

祝你好运！