How do you solve # 2^x = 20#?

1 Answer
Feb 29, 2016

Use basic properties of logarithms to remove #x# from the exponent to find that

#x = log_2(20)~~4.322#

Explanation:

We will use the following properties of logarithms:

  • #log(a^x)=xlog(a)#
  • #log_a(a) = 1#

With these, we have

#2^x = 20#

#=> log_2(2^x) = log_2(20)#

#=>xlog_2(2)=log_2(20)#

#=>x(1)=log_2(20)#

#:.x = log_2(20)~~4.322#