已知a-b=2,ab=-3求代数式(2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)的值是多少?

问题描述:

已知a-b=2,ab=-3求代数式(2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)的值是多少?

(2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)
=2a+3b-2ab-a-4b-ab-3ab-2b+2a
=2a-a+2a+3b-4b-2b-ab-2ab-3ab
=3a-3b-6ab
=3(a-b)-6ab
=3×2-6×(-3)
=6+18
=24