2006-12-14 09:57:23 · 4 answers · asked by Belinda E 1 in Science & Mathematics ➔ Mathematics
D(out) = D(in) = 250t = 250 * (4 - t)
250t = 1000 - 250t
500t = 1000
t = 2
2006-12-14 10:00:27 · answer #1 · answered by roynburton 5 · 0⤊ 0⤋
D/out = 250t
D/in = 250 x (4 - t)
with D/out = D/in
As D/in = D/out we can say mathematically that
250t = 250 x (4 - t)
Expanding the brackets using the distributive rule which states
a(b-c) = ab - ac
We can say mathematically that
250t = (250 X 4) - (250 X t)
therefore
250t = 1000 - 250t
Adding 250t to both sides of the equation gives
250t + 250t = 1000 (the 250t's cancel out on this side)
therefore adding the t's gives
500t = 1000
Therefore dividing both sides of the equation by 500 gives
t = 2
QED
2006-12-14 10:20:09 · answer #2 · answered by Gaz 5 · 0⤊ 0⤋
D/out = D/in so 250t=250(4-t) so250t=1000-250t and so
(250+250)t=1000 so 500t=1000 so t=2
2006-12-15 07:46:38 · answer #3 · answered by keyur vyas 1 · 0⤊ 0⤋
D/out = D/in
250t = 250(4 - t)
250t = 1000 - 250t
500t = 1000
t = 2
2006-12-14 10:10:58 · answer #4 · answered by Kemmy 6 · 0⤊ 0⤋