if xy/x+y =a
xz/x+z=b
yz/y+z=c
where a,b,c are not zero
the x equals:
a)abc/ab+bc+ca
b)2abc/ab+bc+ca
c)2abc/ab+ac-bc
d)2abc/bc+ca-ab
Answers
Answered by
45
xy/(x+y) is the same as 1/(1/x+1/y)
so we can rewrite xy/(x+y) = a
as
1/x+1/y = 1/a (1)
also rewrite xz/(x+z) = b
as
1/x+1/z = 1/b (2)
add (1) and (2)
==> 2/x+1/y+1/z = 1/a+1/b
but we also know that 1/z+1/y = 1/c
so 2/x+1/c = 1/a+1/b
so 2/x = 1/a+1/b-1/c = (bc+ac-ab)/abc
so x = 2abc / (bc+ac-ab)
QED
Answered by
2
Answer:
The required answer is (d)
Step-by-step explanation:
Given that,
Subtracting equation (3) from (1) we get,
Adding equation (2) and (4) we get,
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