(2x+y-3）(2x-y+3)(a三次方b四次方)²÷（ab²）三次方（a-b）²+4ab4xy²-4x²y-y三次方

(2x+y-3）(2x-y+3)(a三次方b四次方)²÷（ab²）三次方（a-b）²+4ab4xy²-4x²y-y三次方
(2x+y-3）(2x-y+3)
(a三次方b四次方)²÷（ab²）三次方
（a-b）²+4ab
4xy²-4x²y-y三次方

(2x+y-3）(2x-y+3)(a三次方b四次方)²÷（ab²）三次方（a-b）²+4ab4xy²-4x²y-y三次方
(2x+y-3）(2x-y+3)
=[2x+(y-3)][2x-(y-3)]
=4x²-(y-3)²
=4x²-y²+6y-9
(a三次方b四次方)²÷（ab²）三次方
=a的6次方b的8次方÷a³b的6次方
=a³b²
（a-b）²+4ab
=a²-2ab+b²+4ab
=a²+2ab+b²
=(a+b)²
4xy²-4x²y-y三次方
=-y(4x²-4xy+y²)
=-y(2x-y)²