已知/a-b-5/+(ab+1)的2次方=0,求（2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)的值,要写过程.

题目

已知/a-b-5/+(ab+1)的2次方=0,求（2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)的值,要写过程.
/ /是绝对值的意思

答案

a-b-5=0,ab+1=0
a-b=5,ab=-1
（2a+3b-2ab)-(a+4b+ab)-(3ab+2b-2a)
=2a+3b-2ab-a-4b-ab-3ab-2b+2a
=(3a-3b)-6ab
=3(a-b)-6ab
=3x5+6
=15+6
=21