已知a、b、c为实数,ab/a+b=1/6,bc/b+c=1/8,ca/c+a=1/10.求分式abc/ab+bc+ca的值.

问题描述:

已知a、b、c为实数,

ab
a+b
1
6
bc
b+c
1
8
ca
c+a
1
10
.求分式
abc
ab+bc+ca
的值.

ab
a+b
1
6
bc
b+c
1
8
ca
c+a
1
10

a+b
ab
=6,
b+c
bc
=8,
c+a
ca
=10,
1
b
1
a
=6
1
c
+
1
b
=8
1
a
+
1
c
=10

1
a
=4,
1
b
=2,
1
c
=6,
1
a
+
1
b
+
1
c
=
bc+ac+ab
abc
=12,
abc
ab+bc+ca
=
1
12