若a-b/b=1/2,则3a-5ab+2b/2b+3ab-5b的值为

问题描述:

若a-b/b=1/2,则3a-5ab+2b/2b+3ab-5b的值为

(a-b)/b=1/2,得:a=3b/2;代入下式 (3a-5ab+2b)/(2a+3ab-5b) =b(27/4-15/2+2)/[b(9/2+9/2-5)] =5/16