1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y)]÷4y 3)
问题描述：
1) (2x+5y)(2x-5y)(-4x^2-25y^2) 2) [（x+y)(x-y)-(x-y)^2+2y(x-y)]÷4y 3)
整式乘除 3）（a+b)^2-2a(b+1)-a^2b÷ab 4）（a^2+3)(a-3)-a(a^2-2a-2）
答
1) (2x+5y)(2x-5y)(-4x^2-25y^2)=-(4x^2-25y^2)(4x^2+25y^2)=-(16x^4-625y^4)=625y^4-16x^42) [（x+y)(x-y)-(x-y)^2+2y(x-y)]÷4y=(x-y)(x+y-x+y+2y)÷4y=4y(x-y)÷4y^=(x-y) 3）（a+b)^2-2a(b+1)-a^2b÷ab=a^2+2a...