5^x=100, solve for x?

Question

explain how to do this please! i know its easy I just cant remember.

Answer 1

5^x=100
talke ln
ln(5^x)=ln(100)
xln(5)=ln(100)
x=ln(100)/ln(5)

Answer 2

Try the definition of logarithm. That number x such that when you raise 5 to it, you get 100, is defined to be:

log(5) 100,

the base-5 logarithm of 100. That's your answer, log(5) 100.

Answer 3

Try log 5^x = log 100
x log 5 = log 100
Use your calculator to give you the answer.

Answer 4

5^x = 100
log(5)100 = x

x = log(5)100

if you want an approximation, then

x = (log(100))/(log(5))
x = about 2.8614

Answer 5

The easiest way to solve problems like this is to set up a logorithm like others have here.

Answer 6

Is that supposed to mean 5 times x = 100?

Kay then....

5^x=100
divide 100 by 5, because that is the inverse operation of multiplication. So you get 20.

x=20

Am I right?

Answer 7

For this question, use logarithms.

5^x = 100

Taking lg on both sides, we have,

lg (5^x) = lg 100
xlg 5 = lg 100
x = (lg 100) / (lg 5)
x = 2.86

Hope this helps.

Answer 8

use common log instead...its easier.

log 5^x =log100
x log 5= 2
x= 2/log 5
x=2.86

Answer 9

x=log(100)/log(5)

Answer 10

xlog5=log100
xlog5=2
x=2/log5
approx. = 2.861353
Check: 5^2.862= 100.104