Question

1 （2x-3y)^2(2x+3y)^2 2 (2x+y-1)(2x+y+y) 3 (2+xy)(xy-2)-(-2+xy)^2 4 (a+3b)^2-(2a-3b)(3b+2a)

麻烦给详解

Answer 1

1.（2x-3y)^2(2x+3y)^2
=[（2x-3y)(2x+3y)]^2
=(4x^2-9y^2)^2
=16x^4-72x^2y^2+81y^4
2.(2x+y-1)(2x+y+y)题目是不是打错了 应该是(2x+y-1)(2x+y+1)吧
=（2x+y)^2-1
=4x^2+4xy+y^2-1
3.(2+xy)(xy-2)-(-2+xy)^2
=(x^2y^2-4)-(x^2y^2-4xy+4)
=x^2y^2-4-x^2y^2+4xy-4
=4xy-8
4.(a+3b)^2-(2a-3b)(3b+2a)
=a^2+6ab+9b^2-4a^2+9b^2
=18b^2-3a^2+6ab

挺费事的。。希望能帮到你。。