log (x+9) - log x=1
2006-12-14 10:30:37 · 6 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x=1
2006-12-14 10:35:58 · answer #1 · answered by Bao L 3 · 0⤊ 0⤋
I assume you are taking log to the base 10. Then:
log (x+9) - log x = 1
log[(x+9)/x] = 1
(x+9)/x = 10
x = 1
2006-12-14 10:41:22 · answer #2 · answered by Northstar 7 · 0⤊ 0⤋
log (x+9) - log x=1
log [(x+9)/x] = log 10^1 (log 10^1 = log 10)
(x+9)/x = 10 /*x
x+9 = 10x
x-10x = -9
-9x = -9 /:-9
x = 1
check:
log (x+9) - log x=1
x = 1
log (1+9) - log 1 = 1
log 10 - log (10^0) = 1
log 10^1 - 0 = 1
1-0 = 1
1 = 1
OK => x = 1
2006-12-14 11:26:38 · answer #3 · answered by Mirta G 2 · 0⤊ 0⤋
log (x+9) - log x=1
log [(x+9)/x]=1
(x+9)/x=10^1
x+9=10x
9x=9
x=1
2006-12-16 04:48:32 · answer #4 · answered by Ranna Renni 2 · 0⤊ 0⤋
(x+9)/x=10
x=1
2006-12-14 10:34:33 · answer #5 · answered by zippo 2 · 0⤊ 0⤋
If you say it's so very simple, why don't you answer it yourself. Good Luck=)
2006-12-14 10:33:15 · answer #6 · answered by NickynJessie H 4 · 0⤊ 0⤋