已知a⼀2=b⼀3≠0,求代数式:(5a-2b)⼀(a눀-4b눀)·(a-2b)的值

2024-12-22 00:13:29
推荐回答(2个)
回答1:

原式=[5a-2b/(a 2b)(a-2b)](a-2b) =5a-2b/a 2b 因为a/2=b/3≠0,所以3a=2b,带入上式 得:5a-2b/a 2b=5a-3a/a 3a=2a/4a=1/2

回答2:

a/2=b/3
∴2b=3a

∴:(5a-2b)/(a²-4b²)·(a-2b)
=(5a-2b)/(a+2b)(a-2b)×(a-2b)
=(5a-2b)/(a+2b)
=(5a-3a)/(a+3a)
=2a/4a
=1/2