How do you solve 10^(5x+2)=5^(4-x)?

1 Answer
Jul 10, 2016

x = (4ln(5)-2ln(10))/(5ln(10)+ln(5))~~0.1397

Explanation:

Using the property that ln(a^x)=xln(a):

10^(5x+2) = 5^(4-x)

=> ln(10^(5x+2)) = ln(5^(4-x))

=>(5x+2)ln(10) = (4-x)ln(5)

=>5ln(10)x+2ln(10) = 4ln(5)-ln(5)x

=>5ln(10)x+ln(5)x = 4ln(5)-2ln(10)

=>(5ln(10)+ln(5))x = 4ln(5)-2ln(10)

=>x = (4ln(5)-2ln(10))/(5ln(10)+ln(5))~~0.1397