How do you solve #5^ { 3x } = 1,000#?

2 Answers
Jun 22, 2018

Solution: # x ~~ 1.43#

Explanation:

# 5^(3 x)= 1000# taking log on both sides we get,

# 3 x log (5)= log(1000)# or

# cancel3* x* 0.69897= cancel3 #

# x= 1/ 0.69897~~ 1.43 (2 dp)#

Solution: # x ~~ 1.43# [Ans]

Jun 22, 2018

Let's solve this problem by converting this into a logarithmic function.

Explanation:

We can first use what I like to call the "swirl rule". This means that in an equation #log_bx=y#, it can rewritten as #b^y=x#. (You can draw a swirling line through each of the variables, hence the name.) This rule also works the other way around. Let's apply this to our equation:

#5^(3x)=1000#
#log_5 1000=3x#

We can then divide each side by 3 to get our answer:

#(log_5 1000)/3=x#
#1.4307~~x#