ohhh.....! I'm sorry , the last row will be :

So , there are 120 kilometres do you live from the station . 

Let {V1=4V2=20

 (km/h)  

We got this :

S=V.t

 (with t is the time , S is the length of roads and V is the speed)

⇒⎧⎪ ⎪ ⎪⎨⎪ ⎪ ⎪⎩t1=SV1t2=SV2

From the topic :

t1=t2+24

  (minute)

⇔SV1=SV2+24

⇔S4=S20+24

⇔S4=S+24.2020

<=> 20S = 4S + 4.20.24

<=> 16S = 4.20.24

<=> S = 120 (km)

So , there are 20 kilometres do you live from the station .

Let \(\left\{{}\begin{matrix}V_1=4\\V_2=20\end{matrix}\right.\) (km/h)  

We got this :

\(S=V.t\) (with t is the time , S is the length of roads and V is the speed)

\(\Rightarrow\left\{{}\begin{matrix}t_1=\dfrac{S}{V_1}\\t_2=\dfrac{S}{V_2}\end{matrix}\right.\)

From the topic :

\(t_1=t_2+24\)  (minute)

\(\Leftrightarrow\dfrac{S}{V_1}=\dfrac{S}{V_2}+24\)

\(\Leftrightarrow\dfrac{S}{4}=\dfrac{S}{20}+24\)

\(\Leftrightarrow\dfrac{S}{4}=\dfrac{S+24.20}{20}\)

<=> 20S = 4S + 4.20.24

<=> 16S = 4.20.24

<=> S = 120 (km)

So , there are 20 kilometres do you live from the station .