2m-3n）²（2m+3n）²

（2m+3n）的平方·（3n-2m）的平方
=[(2m+3n)(2m-3n)]²
=(4m²-9n²)²
=16m^4-72m²n²+81n^4
(x-3y+1)(x+3y-1)
=[x-(3y-1)][x+(3y-1)]
=x^2-9(y^2)+6y-1
(3x+2y)(2x-3y)
=3x*2x+3x*(-3y)+2y*2x+2y*(-3y)
=6x^2-9xy+4xy-6y^2
=6x^2-5xy-6y^2
(5m+1)²-(5m+1)(5m-1)
=(5m+1)[5m+1-(5m-1)]
=(5m+1)(5m+1-5m+1)
=(5m+1)2
=2(5m+1)
（4X+1)(4X-1)-(2X-5)(2X+3)
=16x^2-1-(4x^2-4x-15)
=16x^2-1-4x^2+4x+15
=16x^2-4x^2+4x+15-1
=12x^2+4x+14
望采纳啊啊啊