132k views
4 votes
Given that

2 {}^(x) = 0.125
Find x


User Trung Tran
by
4.6k points

2 Answers

3 votes

Answer:

x = -3.

Explanation:

2^x = 0.125

Taking logs:

x ln 2 = ln 0.125

x = ln 0.125 / ln 2

x = -3

User Mathias Hillmann
by
4.1k points
5 votes
Take the natural log of both sides

ln(2^x)=ln(.125)
Xln(2)=ln(.125)
X=ln(.125)/ln(2)
X=-3

ALTERNATIVE ROUTE:
You know that 0.125 is equal to 1/8
And 1/2^3 is also equal to 1/8
So since you need the reciprocal to match it the exponent is a negative
User Jesuisgenial
by
4.7k points