Question 1049609
line skater
speed {{{r}}}
time {{{t}}}
distance {{{30}}}
{{{30}}}={{{rt}}}
{{{30/(r)}}}={{{t}}}
cyclist
speed {{{r+9}}}
time {{{t}}}
distance {{{45}}}

{{{30}}}/{{{r}}}={{{t}}}
{{{45}}}/{{{r+9}}}={{{t}}}

{{{30/(r)}}}={{{45}}}/{{{r+9}}}
{{{r/(30)}}}={{{r+9}}}/{{{45}}}
{{{45r}}}={{{30r+270}}}
{{{45r-30r}}}={{{270}}}
{{{15r}}}={{{270}}}
{{{r}}}={{{18}}}
hence for the line skater
{{{r}}}={{{18}}}

for the cyclist
{{{r}}}={{{18+9}}}
{{{r}}}={{{27}}}