已知a,b,c三个数满足ab/a+b=1/3 ,bc/b+c=1/4,ca/c+a=1/5,那么abc/ab+bc+ca的值为?将已知条件全部倒数,得:(a+b)/(ab)=3 ,(b+c)/(bc)=4 ,(a+c)/(ac)=5 则1/a=2,1/b=1 ,1/c=3 (ab+bc+ac)/(abc)=1/a+1/b+1/c=6 所以(abc)/(ab+bc+ac)=1/6为什
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![已知a,b,c三个数满足ab/a+b=1/3 ,bc/b+c=1/4,ca/c+a=1/5,那么abc/ab+bc+ca的值为?将已知条件全部倒数,得:(a+b)/(ab)=3 ,(b+c)/(bc)=4 ,(a+c)/(ac)=5 则1/a=2,1/b=1 ,1/c=3 (ab+bc+ac)/(abc)=1/a+1/b+1/c=6 所以(abc)/(ab+bc+ac)=1/6为什](/uploads/image/z/3719971-19-1.jpg?t=%E5%B7%B2%E7%9F%A5a%2Cb%2Cc%E4%B8%89%E4%B8%AA%E6%95%B0%E6%BB%A1%E8%B6%B3ab%2Fa%2Bb%3D1%2F3+%2Cbc%2Fb%2Bc%3D1%2F4%2Cca%2Fc%2Ba%3D1%2F5%2C%E9%82%A3%E4%B9%88abc%2Fab%2Bbc%2Bca%E7%9A%84%E5%80%BC%E4%B8%BA%3F%E5%B0%86%E5%B7%B2%E7%9F%A5%E6%9D%A1%E4%BB%B6%E5%85%A8%E9%83%A8%E5%80%92%E6%95%B0%2C%E5%BE%97%EF%BC%9A%28a%2Bb%29%2F%28ab%29%3D3+%2C%28b%2Bc%29%2F%28bc%29%3D4+%2C%28a%2Bc%29%2F%28ac%29%3D5+%E5%88%991%2Fa%3D2%2C1%2Fb%3D1+%2C1%2Fc%3D3+%28ab%2Bbc%2Bac%29%2F%28abc%29%3D1%2Fa%2B1%2Fb%2B1%2Fc%3D6+%E6%89%80%E4%BB%A5%28abc%29%2F%28ab%2Bbc%2Bac%29%3D1%2F6%E4%B8%BA%E4%BB%80)
已知a,b,c三个数满足ab/a+b=1/3 ,bc/b+c=1/4,ca/c+a=1/5,那么abc/ab+bc+ca的值为?将已知条件全部倒数,得:(a+b)/(ab)=3 ,(b+c)/(bc)=4 ,(a+c)/(ac)=5 则1/a=2,1/b=1 ,1/c=3 (ab+bc+ac)/(abc)=1/a+1/b+1/c=6 所以(abc)/(ab+bc+ac)=1/6为什
已知a,b,c三个数满足ab/a+b=1/3 ,bc/b+c=1/4,ca/c+a=1/5,那么abc/ab+bc+ca的值为?
将已知条件全部倒数,得:
(a+b)/(ab)=3 ,(b+c)/(bc)=4 ,(a+c)/(ac)=5
则1/a=2,1/b=1 ,1/c=3
(ab+bc+ac)/(abc)=1/a+1/b+1/c=6
所以(abc)/(ab+bc+ac)=1/6
为什么 (ab+bc+ac)/(abc)=1/a+1/b+1/c 怎么变的形?
已知a,b,c三个数满足ab/a+b=1/3 ,bc/b+c=1/4,ca/c+a=1/5,那么abc/ab+bc+ca的值为?将已知条件全部倒数,得:(a+b)/(ab)=3 ,(b+c)/(bc)=4 ,(a+c)/(ac)=5 则1/a=2,1/b=1 ,1/c=3 (ab+bc+ac)/(abc)=1/a+1/b+1/c=6 所以(abc)/(ab+bc+ac)=1/6为什
(ab+bc+ac)/(abc)
=ab/(abc)+bc/(abc)+ac/(abc)
=1/a+1/b+1/c
ab/a+b=1/3 ,所以 (a+b)/ab =3, 1/a + 1/b =3
同理1/b + 1/c =4 , 1/a + 1/c = 5
将这三个式子加起来 2(1/a + 1/b + 1/c) = (3+4+5) = 12
那么 (ab+bc+ac)/abc = 1/a + 1/b + 1/c = 6
所以 abc/(ab+bc+ca) = 1/6
倒过来想。把1/a+1/b+1/c 通分就得(ab+bc+ac)/(abc)
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