3^x = 81
2007-01-17 22:28:33 · 10 answers · asked by Matthew K 2 in Science & Mathematics ➔ Mathematics
For this question, you have to use logarithms,
so, taking the log of both sides:
log 3^x = log 81
x log 3 = log 81 [since: log a^p = p log a]
now solve for x:
x = log 81/log 3
x = 4
2007-01-17 22:35:10 · answer #1 · answered by thugster17 2 · 0⤊ 0⤋
3*3*3*3 = 3^4 = 81, therefore x=4
2007-01-17 22:32:30 · answer #2 · answered by chrisatmudd 4 · 0⤊ 0⤋
well , you should solve this problem with log . and the way is easy . you should convert it some how . i mean you should say what would be the log81,3 and then you can find the answer . but if you didn't still learned to solve log problems don't worry ! just use your mind !! you should 81 = 3*3*3*3 . right ??
so the X is 4 . easy , huh ??
2007-01-17 22:41:25 · answer #3 · answered by arash 3 · 0⤊ 0⤋
x=4
2007-01-17 22:38:14 · answer #4 · answered by yogesh gulhania 2 · 0⤊ 0⤋
4
3^4=81
2007-01-17 22:32:20 · answer #5 · answered by Bill F 6 · 0⤊ 0⤋
Lets see 3X3 is 9 X3 is 27 X3 is 81. so x is 4
2007-01-17 22:34:09 · answer #6 · answered by Anonymous · 0⤊ 0⤋
taking log of both sides and remember 81=3^4
xlog3=4log3 so x=4
2007-01-17 22:33:00 · answer #7 · answered by santmann2002 7 · 0⤊ 0⤋
X equals 4
2007-01-17 23:15:40 · answer #8 · answered by TJ 2 · 0⤊ 0⤋
3^x = 81
3^x = 3^4
x = 4
><
2007-01-18 07:20:08 · answer #9 · answered by aeiou 7 · 0⤊ 0⤋
3^x=(3)^4
bases are equal and so powers should be equal
therefore x=4
2007-01-18 00:03:09 · answer #10 · answered by srinu710 4 · 0⤊ 0⤋