(2a-3b)(3a-4b)=0,求a^2-2ab/(a+b)(a-2b)的值

(2a-3b)(3a-4b)=0,求a^2-2ab/(a+b)(a-2b)的值
(2a-3b)(3a-4b)=0,求a^2-2ab/(a+b)(a-2b)的值

(2a-3b)(3a-4b)=0,求a^2-2ab/(a+b)(a-2b)的值
(2a-3b)(3a-4b)=0
2a-3b=0 a=3b/2
3a-4b=0 a=4b/3
a²-2ab/(a+b)(a-2b)
=a(a-2b)/(a+b)(a-2b)
=a/(a+b)
(1)当 a=3b/2
原式=(3b/2)/(3b/2+b)
=(3b/2)/(5b/2)
=3/5
(2)当a=4b/3
原式=(4b/3)/(4b/3+b)
=(4b/3)/(7b/3)
=4/7