1/a - 1/b =5求2a+3ab-2b/a-ab-b的值

1/a - 1/b =5求2a+3ab-2b/a-ab-b的值
1/a - 1/b =5
求2a+3ab-2b/a-ab-b的值

1/a - 1/b =5求2a+3ab-2b/a-ab-b的值
由已知变形,得
b-a=5ab
代入下式,得
(2a+3ab-2b)/(a-ab-b)
=[3ab-2(b-a)]/[-ab-(b-a)]
=[3ab-2×5ab]/[-ab-5ab]
=-7ab/(-6ab)
=7/6
因此,(2a+3ab-2b)/(a-ab-b)的值是7/6.

wei 2