If a unit wants to organize a basketball league match, the competition system is a single cycle form (every two teams have a match), and it plans to arrange 10 matches, then the teams participating in the match should have______ ．

If a unit wants to organize a basketball league match, the competition system is a single cycle form (every two teams have a match), and it plans to arrange 10 matches, then the teams participating in the match should have______ ．

Let's invite x teams to participate in the game, and get 1 + 2 + 3 + according to the title +X-1 = 10, that is, X (x − 1) 2 = 10, ∧ x2-x-20 = 0, ∧ x = 5 or x = - 4

(1) In order to organize a basketball league match, the competition system is in the form of single circulation, and 15 matches are planned. How many teams should be invited to participate in the match
(2) How to encircle a 50 square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square square

Six teams can be invited. In a single round, there are exactly five rounds, three games in each round, a total of 15 games. After the end of the single round, the team will win the championship directly, which is similar to the competition system of Stankovic cup

Party A and Party B contract a project to be completed within 10 days. If they do it alone, Party A will take 8 days less than Party B. If Party A does it alone, it will take X days

The whole project quantity is 1, the speed of Party A is V1, and the speed of Party B is v2,
1/v1=x,1/v2=x+8,
V1 = 1 / x, V2 = 1 / (x + 8), substituting V1 and V2 into 1 / (V1 + V2) = 10, X (x + 8) / (2x + 8) = 10, sorting out x ^ 2-12x-80 = 0

The solution of the equation 5x-2m + - 4-x of X satisfies 2

The middle one should be the equal sign
Bring in x = 2 and x = 10 respectively,
10-2m=-6
16=2m
m=8
50-2m=-14
m=32
So, 8