18a2-32b2-18a+24b.

问题描述:

18a2-32b2-18a+24b.

18a2-32b2-18a+24b
=2(9a2-16b2-9a+12b)
=2[(9a2-16b2)-3(3a-4b)]
=2[(3a+4b)(3a-4b)-3(3a-4b)]
=2(3a-4b)(3a+4b-3).