How do you solve 2^x = 202x=20?

1 Answer
Feb 29, 2016

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

x = log_2(20)~~4.322x=log2(20)4.322

Explanation:

We will use the following properties of logarithms:

  • log(a^x)=xlog(a)log(ax)=xlog(a)
  • log_a(a) = 1loga(a)=1

With these, we have

2^x = 202x=20

=> log_2(2^x) = log_2(20)log2(2x)=log2(20)

=>xlog_2(2)=log_2(20)xlog2(2)=log2(20)

=>x(1)=log_2(20)x(1)=log2(20)

:.x = log_2(20)~~4.322