2007-02-20 22:03:52 · 6 answers · asked by phoenixmkm 1 in Science & Mathematics ➔ Mathematics
(1/a)=(1/b)+(1/c)
1/(1/a)=1/( (1/b)+(1/c) )
a=1/( (c/bc)+(b/bc) )
a=1/( (b+c)/bc )
a=bc/(b+c)
2007-02-20 22:14:11 · answer #1 · answered by costasgr43 2 · 0⤊ 0⤋
get a common denominator on the right:
1/b + 1/c = (c+b)/bc
Now cross multiply:
1/a = (c+b)/bc
bc = a(c+b)
a = bc/(c+b)
2007-02-20 22:12:44 · answer #2 · answered by Mathematica 7 · 0⤊ 0⤋
multiple a both side, (1/a)(a)=(1/b)(a)+(1/c)(a)
then, 1=a/b+a/c
then, make the same factor, 1=(a/b)(c/c)+(a/c)(b/b)
then, 1=ac/bc+ab/bc
then, 1=(ac+ab)/bc
then, 1=(a)(c+b)/bc
then, a=bc/(c+b)
2007-02-20 22:18:57 · answer #3 · answered by fk l 1 · 0⤊ 0⤋
1/a = 1/b + 1/c
1/a = (c + b) / bc
a = bc / (b + c)
2007-02-20 22:15:55 · answer #4 · answered by Como 7 · 0⤊ 0⤋
1/a=1/b+1/c
1/a=(b+c)/bc
there fore a=bc/(b+c)
eg 1/a=1/2+1/3
1/a=5/6
a=6/5
2007-02-20 22:14:02 · answer #5 · answered by KingSAT 2 · 0⤊ 0⤋
(1/a)=(1/b)+(1/c)
=> 1/a ={(b+c)/bc}
Therefore, a=bc/(b+c)
2007-02-20 22:13:04 · answer #6 · answered by alpha 7 · 0⤊ 0⤋