Here you go.
I was sorta unsure how to read the last part in your question but I tried my best to interpret it

0.00001933 = 1.933 x 10^{-5}
Length = 13 = (x + 3)
Width = 14 = (x + 4)
x2 + 7x + 12 = area of the rectangle
can be factored into
(x + 3)(x + 4)
Let L = one of the factors (x + 3)
Let W = the other factor (x + 4)
If x = 10 then
(10 + 3) = 13 = L
(10 + 4) = 14 = W
Checking this can be checked a couple of ways
Plug x = 10 into the original equation
x2 + 7x + 12
102 + 7(10) 12 = 100 + 70 + 12 = 182 = Area
Multiplty the factors
L x W = 13 x 14 = 182 = Area
I hope you find this useful if you have any questions please send me a message.
There are 4 teams in total and each team has 7 members. One of the team will be the host team.
Tournament committee will be made from 3 members from the host team and 2 members from each of the three remaining teams. Selecting the members for tournament committee is a combinations problem. We have to select 3 members out 7 for host team and 2 members out of 7 from each of the remaining 3 teams.
So total number of possible 9 member tournament committees will be equal to:

This is the case when a host team is fixed. Since any team can be the host team, there are 4 possible ways to select a host team. So the total number of possible 9 member tournament committee will be:

Therefore, there are 2917215 possible 9 member tournament committees