Question

1.如果x^2-y^2=4,求（x-y)^2(x-y)^2的值 2.计算（a+b)^2(a^2-

2ab+b^2)
3.计算(x-y+2)^2-(x-y)^2
4.若a^2+b^2+2a-6b+10=0,试求a^b的值
5.（x+2y-4)(x-2y+4)6.（m+1）（m-1）（m^2-1)
急！

Answer 1

x^2-y^2=4,求（x+y)^2(x-y)^2
（x+y)^2(x-y)^2=（x^2-y^2)^2=4^2=16

2.计算（a+b)^2(a^2-2ab+b^2)=(a+b)²(a-b)²=(a²-b²)²=a^4-2a²b²+b^4
3.计算(x-y+2)^2-(x-y)^2=(x-y)²+4(x-y)+4-(x-y)²=4x-4y+4
4.若a^2+b^2+2a-6b+10=0,试求a^b的值
a²+2a+1+b²-6b+9=0
(a+1)²+(b-3)²=0
完全平方非负
所以a=-1，b=3
5.（x+2y-4)(x-2y+4)
=[x+(2y-4)][x-(2y-4)]=x²-(2y-4)²=x²-4y²+16y+16