E等于A ?后面的应该不会成立即使成立也必须满足b等于0 ?是等价的 ?所以a=1,b
=0 c=1
(1/a 1/b 1/c)^2=1/a^2 1/b^2 1/c^2 2/ab 2/ac 2/bc
(1/a 1/b 1/c)^2=1/a^2 1/b^2 1/c^2 2(a b c)/abc
1/a^2 1/b^2 1/c^2=(1/a 1/b 1/c)^2-2(a b c)/abc
=(-4)^2-0
=16
什么什么啊
答：b:a=2/3:9/4=8:27=56:189, a:c=7/4:5/2=7:10=189:270, ∴a:b:c=189:56:270.详情>>
答：详情>>
