30 POINTS!! WHOEVER ANSWERS FIRST GETS BRAINIEST ANSWER!!
______________
United States | 104|
China | 88|
Russia | 82|
Great Britain | x |
Germany | 44|
Japan | 38 |

The table shows the total medal counts for the top 6 medal winning countries at the 2012 Summer Olympic Games. The top 6 earned a total of 421 medals at the games. Based on the information in the table, write an expression that represents the total amount of medals earned by these countries.

How can you use your expression and the information given to determine the number of medals Great Britain earned? Explain your reasoning.