Answer:
Option C - Simplify the right side using the "difference of two logs is the log of the quotient" property.
Step-by-step explanation:
Given : Expression 
To find : What is the first step in solving the expression ?
Solution :
Expression 
Step 1 - Simplify the right side using the "difference of two logs is the log of the quotient" property.
i.e. 
Apply the first step we get,

Therefore, Option C is correct.
let's firstly convert the mixed fractions to improper fractions and then proceed.
![\stackrel{mixed}{4\frac{1}{2}}\implies \cfrac{4\cdot 2+1}{2}\implies \stackrel{improper}{\cfrac{9}{2}}~\hfill \stackrel{mixed}{1\frac{1}{4}}\implies \cfrac{1\cdot 4+1}{4}\implies \stackrel{improper}{\cfrac{5}{4}} \\\\[-0.35em] ~\dotfill](https://tex.z-dn.net/?f=%5Cstackrel%7Bmixed%7D%7B4%5Cfrac%7B1%7D%7B2%7D%7D%5Cimplies%20%5Ccfrac%7B4%5Ccdot%202%2B1%7D%7B2%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B9%7D%7B2%7D%7D~%5Chfill%20%5Cstackrel%7Bmixed%7D%7B1%5Cfrac%7B1%7D%7B4%7D%7D%5Cimplies%20%5Ccfrac%7B1%5Ccdot%204%2B1%7D%7B4%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B5%7D%7B4%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill)
![\begin{array}{ccll} miles&hours\\ \cline{1-2} \frac{9}{2}&\frac{5}{4}\\[1em] x&1 \end{array}\implies \cfrac{~~ \frac{9}{2}~~}{x}=\cfrac{~~ \frac{5}{4}~~}{1}\implies \cfrac{~~ \frac{9}{2}~~}{\frac{x}{1}}=\cfrac{5}{4}\implies \cfrac{9}{2}\cdot \cfrac{1}{x}=\cfrac{5}{4} \\\\\\ \cfrac{9}{2x}=\cfrac{5}{4}\implies 36=10x\implies \cfrac{36}{10}=x\implies \cfrac{18}{5}=x\implies 3\frac{3}{5}=x](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bccll%7D%20miles%26hours%5C%5C%20%5Ccline%7B1-2%7D%20%5Cfrac%7B9%7D%7B2%7D%26%5Cfrac%7B5%7D%7B4%7D%5C%5C%5B1em%5D%20x%261%20%5Cend%7Barray%7D%5Cimplies%20%5Ccfrac%7B~~%20%5Cfrac%7B9%7D%7B2%7D~~%7D%7Bx%7D%3D%5Ccfrac%7B~~%20%5Cfrac%7B5%7D%7B4%7D~~%7D%7B1%7D%5Cimplies%20%5Ccfrac%7B~~%20%5Cfrac%7B9%7D%7B2%7D~~%7D%7B%5Cfrac%7Bx%7D%7B1%7D%7D%3D%5Ccfrac%7B5%7D%7B4%7D%5Cimplies%20%5Ccfrac%7B9%7D%7B2%7D%5Ccdot%20%5Ccfrac%7B1%7D%7Bx%7D%3D%5Ccfrac%7B5%7D%7B4%7D%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B9%7D%7B2x%7D%3D%5Ccfrac%7B5%7D%7B4%7D%5Cimplies%2036%3D10x%5Cimplies%20%5Ccfrac%7B36%7D%7B10%7D%3Dx%5Cimplies%20%5Ccfrac%7B18%7D%7B5%7D%3Dx%5Cimplies%203%5Cfrac%7B3%7D%7B5%7D%3Dx)
Answer: 90 Earth years.
Step-by-step explanation:
Analizing the information provided in the exercise, you need to find the Least Common Multiple (LCM) of the given numbers.
You can follow these steps:
1. You must descompose 6, 9, 15 and 18 into their prime factors:

2. Finally, you need to choose the commons and non commons with their greatest exponents and multiply them. Then you get:

Therefore, it will take 90 Earth years for them to all line up.