a. 9/2
b.10/9
c. 2/9
d. 9/10
2007-03-23 04:09:03 · 4 answers · asked by jakw w 1 in Science & Mathematics ➔ Mathematics
(1/81)^t=243^t-2
(1/3^-4)^t = 3^5t-2
-4t = 5t - 2
-4t - 5t = -2
-9t = -2
t = 2/9
Answer c).
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2007-03-23 04:42:57 · answer #1 · answered by aeiou 7 · 0⤊ 2⤋
1 = 81^(t) x 243^(t - 2)
1 = 81^(t) x (3 x 81)^(t - 2)
1 = 81^(t) x 3^(t - 2) x 81^(t - 2)
1 = 3^(t - 2) x 81^(2t - 2)
1 = 3^(t - 2) x 3^(8t - 8)
1 = 3^(9t - 10)
3^(10) = 3^(9t)
t = 10/9
ANSWER b
2007-03-23 14:36:38 · answer #2 · answered by Como 7 · 1⤊ 0⤋
So (3^-4)^t = (3^5)^(t-2) assuming t-2 is the exponent...
â 3^(-4t) = 3^(5t - 10) multiplying exponents
â -4t = 5t - 10
you can take it from here.
2007-03-23 11:44:09 · answer #3 · answered by Anonymous · 2⤊ 0⤋
1/3^-4t=3^5(t-2)
-4t=5t-10
-9t=-10
t=10/9
The answer is b.
Check:
(1/81)^(10/9)=243^((10/9)-2)
.000757=243^(-8/9)
.007576=.007576
2007-03-23 11:49:05 · answer #4 · answered by Anonymous · 1⤊ 0⤋