Question 1066884
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In a​ round-robin chess​ tournament, each player is paired with every other player once. 
The​ function, shown​ below, models the number of chess​ games, N, that must be played in a​ 
round-robin tournament with t chess players. In a​ round-robin chess​ tournament, 6 games were played. 
How many players entered the​tournament?

how to solve formula? N=t^2-t / 2
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<pre>
You need to solve the equation {{{(t^2-t)/2}}} = 6.

Multiply both sides by 2. You will get an equivalent equations

{{{t^2-t}}} = 12,

{{{t^2 -t - 12}}} = 0,

(t-4)*(t+3) = 0.

The roots are t= 4 and t= -3.

Since you need integer positive solution, the only one is t= 4.


<U>Answer</U>. 4 players.
</pre>