SOLUTION: In a round-robin tennis tournament, every player meets every other player exactly once. How many players can participate in a tournament of 45 matches?

Question 131197: In a round-robin tennis tournament, every player meets every other player exactly once. How many players can participate in a tournament of 45 matches?
Answer by scott8148(6628) (Show Source): You can put this solution on YOUR website!
let x="number of players" __ each player plays x-1 matches BUT a vs b is the same as b vs a
__ so the number of matches is x(x-1)/2

x(x-1)/2=45 __ multiplying by 2 and subtracting 90 __ x^2-x-90=0

factoring __ (x+9)(x-10)=0 __ x+9=0 and x-10=0
RELATED QUESTIONS
In a round robin tennis tournament, every player plays against every other player. If 11... (answered by ewatrrr,edjones)

Need Help Please There are 5 tennis players in a tournament. Of each tennis player... (answered by checkley77,rtp1986)

In a round-robin chess tournament, each player is paired with every other... (answered by jim_thompson5910,ikleyn)

In a round-robin chess tournament, each player is paired with every other... (answered by ikleyn)

Suppose five tennis players have made the finals. If each of the five players is to play... (answered by stanbon)

Amy, Linda, Mark, Kelsie, Ryan, Angie, and Matthew are the seven players in a round-robin (answered by ikleyn)

Can somebody please confirm if my answer is correct? My wild guess is 11. But if I am to... (answered by AnlytcPhil)

10 players participate in a tennis tournament. A game involves two players and each... (answered by Boreal)

At a tennis tournament, each player played each other player one time. At the end of the (answered by ikleyn)