Let x be the total number of people who could have voted. We know that 4/25 didn't vote, so the actual number of people who voted is the remaining 21/25 of x.
Out of these people, 4/7 voted for the winner:
![(21)/(25)x\cdot(4)/(7)=(12)/(25)x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/yqaf6hl63591hu19en8e5lp0o0nh2w6mu6.png)
We know that this fraction resulted in 4956 votes, solving for x we have
![x=(4956\cdot 25)/(12)=10325](https://img.qammunity.org/2020/formulas/mathematics/middle-school/an3ae6qel7e3d043bi7igx7i1j7y5ky5pd.png)
So, 10325 people could have voted. But we know that 4/25 didn't vote, while the remaining 21/25 did. So, the number of voters who took part to the election is
![10325\cdot 21/25=8673](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ignfwaoacqq86pz4v9e6nymn3tr7ah5zti.png)
Just for checking, we have indeed
![8673\cdot (4)/(7)=4956](https://img.qammunity.org/2020/formulas/mathematics/middle-school/2n5todrmi2q425jagjn1r7v6e6mw4jthav.png)
which confirms the result.