The answers would be E and F -6 and -3
<span>Each team in the softball league plays each of the other teams exactly once. For every game, there is 2 team playing. The order is not important because A vs B is same as B vs A
So you just need to makes a combination of 2 that have a result of 21. If there is t number of teams, the number of matches would be:
tC2 = t!/2!(t-2)! = 21
</span>t! / (t-2)! = 21 *2
(t)(t-1)= 42
t^2 -t -42=0
(t-7)(t+6)
t=7 ; t=-6
Excluding the minus result, you got 7 teams.
Answer: 
Step-by-step explanation:
1. Substitute
into first equation and solve for "x" in order to find the x-intercept of the first line:

2. Substitute
into the first equation and solve for "y" in order to find the y-intercept of the first line:

Knowing that first line passes through the points
and
, you can graph it.
3. Substitute
into second equation and solve for "x" in order to find the x-intercept:

4. Substitute
into the second equation and solve for "y" in order to find the y-intercept of the second line:

Knowing that second line passes through the points
and
, you can graph it.
The solution of the system of equations is the point of intersection between the lines. Therefore, the solution of this system is:

So the probability is the number of favorable outcomes divided by the number of total outcomes. This means that the favorable outcomes are 7/9, and the unfavorable outcomes are 2/9. The odds against the event are the unfavorable outcomes. Therefore the odds against the event is 2/9, or 0.2 repeating. Hope this helps. Feel free to ask more questions, and feel free to ask questions about my explanation.