if v/a=e/b=f/c
why is it true these three things are equal to (v-e+f)/(a+b+c)?
ie. how do u get from v/a=e/b=f/c to
v/a=e/b=f/c=(v-e+f)/(a+b+c)
2006-12-07 07:23:04 · 3 answers · asked by Milo 4 in Science & Mathematics ➔ Mathematics
sorry it should be (v-e+f)/(a-b+c) i think
so there is a minus between a and b
2006-12-07 07:30:45 · update #1
Thats not true.. (eg take the fractions to be 1/2, 2/4, 3/6. Then you get 2/12, which isn't 1/2).
However, it is true for (v+e+f)/(a+b+c).
Just let x = v/a = e/b = f/c. Then v = ax, e = bx, f = cx, so (v+e+f)/(a+b+c) = (ax+bx+cx)/(a+b+c) = x.
Edit - and that works just the same for (v-e+f)/(a-b+c): you have (ax - bx + cx)/(a-b+c) = x(a-b+c)/(a-b+c) = x.
2006-12-07 07:31:05 · answer #1 · answered by stephen m 4 · 1⤊ 0⤋
i don't think the last equation is valid
(try plugging in arbitrary numbers, and then you'll see what i'm saying)
2006-12-07 07:29:25 · answer #2 · answered by orca1006 2 · 0⤊ 0⤋
it is a property of ratios and proportions
2006-12-07 07:27:04 · answer #3 · answered by raj 7 · 0⤊ 1⤋