若(a-b)/b=1/2 则（3a²-5ab+2b²)/(2a²+3ab-5b²)的值是

若(a-b)/b=1/2 则（3a²-5ab+2b²)/(2a²+3ab-5b²)的值是
若(a-b)/b=1/2 则（3a²-5ab+2b²)/(2a²+3ab-5b²)的值是

若(a-b)/b=1/2 则（3a²-5ab+2b²)/(2a²+3ab-5b²)的值是
2(a-b)=b
2a-2b=b
所以b=2a/3
原式=(3a²-10a²/3+8a²/9)/(2a²+2a²-20a²/9)
=(3-10/3+8/9)/(2+2-20/9)
=5/16

若(a-b)/b=1/2 ,则a/b-1=1/2 即a/b=3/2
原式=(a-b)(3a-2b)/(a-b)(2a+5b)=(3a-2b)/(2a+5b)＝(3a/b-2)/(2a/b+5)=(3*3/2-2)/(2*3/2+5)=5/16