解法一
(2a-3b)^2-(3a-2b)^2
=[(2a-3b)+(3a-2b)][(2a-3b)-(3a-2b)]
=(2a-3b+3a-2b)(2a-3b-3a+2b)
=(5a-5b)(-a-b)
=5(a-b)(-a-b)
=5(b^2-a^2)
=5b^2-5a^2
解法二
(2a-3b)^2-(3a-2b)^2
=4a^2-12ab+9b^2-(9a^2-12ab+4b^2)
=4a^2-12ab+9b^2-9a^2+12ab-4b^2
___```````
=-5a^2+5b^2