Question 301597
What are the issues? 
What part are you lost on? Please be specific. 
It's a pretty straightforward question. 
Pick three x values greater than 1: 2,3,4.
Three x values between zero and 1: (1/8),(1/4), (1/2)
Include x=1. 
Evaluate the function at those points.
Use a calculator or EXCEL. 
{{{x=(1/8)}}}, {{{y=log(5/8)=-0.204}}}
{{{x=(1/4)}}}, {{{y=log(5/4)= 0.097}}}
{{{x=(1/2)}}}, {{{y=log(5/2)= 0.398}}}
{{{x=1}}}, {{{y=log(5)= 0.699}}}
{{{x=2}}}, {{{y=log(10)= 1}}}
{{{x=3}}}, {{{y=log(15)= 1.176}}}
{{{x=4}}}, {{{y=log(20)= 1.301}}}
Now plot the x-y pairs.
{{{drawing(300,300,-1,5,-1,5,
circle(1/8,-0.204,.15),
circle(1/4, 0.097,.15),
circle(1/2, 0.398,.15),
circle(1,0.699,.15),
circle(2,1,.15),
circle(3,1.176,.15),
circle(4,1.301,.15),grid(1),
graph(300,300,-1,5,-1,5,log(10,5x))

)}}}
If you look at the graph, there is a limit as x approaches 0 which would be a vertical asymptote at {{{x=0}}}. 
That's the only one.