2007-07-15 07:56:09 · 9 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
take log base 25 to each side
log25 25^(x-1) = log25 125
x-1=1.5
x=2.5
2007-07-15 07:59:43 · answer #1 · answered by leo 6 · 1⤊ 1⤋
OK... follow these steps...
1. Take the log of both sides of the equation:
log [25^(x-1)]=log 125
2. Properties of logarithms says you can rewrite the result like this:
(x-1)(log 25)=log 125
3. Divide both sides by log 25:
x-1=log 125/log 25
4. Use your calculator to simplify the right side of the equation:
x-1=1.5
5. Add 1 to both sides.
x=2.5
There's your answer. Substitute it back into the original equation to check it.
2007-07-15 08:05:18 · answer #2 · answered by JohnnyBNYC 2 · 0⤊ 0⤋
(x - 1) log 25 = log 125
(x - 1) = log 125 / log 25
Take log as being log base 5 :-
(x - 1) = 3 / 2
x = 5 / 2
2007-07-15 08:52:13 · answer #3 · answered by Como 7 · 0⤊ 0⤋
We have:
25^(x-1) = 125.
Then by exponential:
(5^2)^(X-1) = 5^3
5^(2(X-1) =5^3
Then the exponents are equals because your bases are equals:
2(X-1) = 3
Then X= 3/2 + 1
X = 5/2
**********
2007-07-15 08:18:35 · answer #4 · answered by CHARTIGER 2 · 0⤊ 0⤋
25 ^ x-1 = 125
(5^2)^(x-1) = 5^3
5^(2x-2) = 5^3
2x-2 = 3
2x = 5
x = 5/2
2007-07-15 08:01:30 · answer #5 · answered by onlyhope 3 · 0⤊ 0⤋
5^(2x-2)=5^3 2x-2=3 x=5/2
Just set each side to powers of 5. The exponents must be equal, so solve for x.
2007-07-15 07:59:39 · answer #6 · answered by hazel b grand 2 · 0⤊ 0⤋
log25(125) = 1.5
x-1 = 1.5,
x = 2.5
2007-07-15 08:00:20 · answer #7 · answered by Anonymous · 0⤊ 0⤋
25^(X-1)=125
OR (5^2)^(X-1)=5^3
OR 5^2(X-1)=5^3
OR2(X-1)=3
OR2X-2=3
OR 2X=5
OR X=5/2
2007-07-15 08:04:09 · answer #8 · answered by MAHAANIM07 4 · 0⤊ 0⤋
25^(x-1)=125
5^=(2x-2)=5^3
2x-2=3
2x=5
x=5/2.ANS.
2007-07-15 08:00:06 · answer #9 · answered by Anonymous · 0⤊ 0⤋