X-5+5x-12=25
x+5x=25+5+12
6x=42
x=42/6
x=7
Answer:
3432
Step-by-step explanation:
Total bands = 14
Bands played = 7
The possible lineups can be calculated using Combination.
So, the possible lineups are 14C7
=> 
=> 3432
The values of x and y are 0.2 and 0.4 respectively.
<em><u>Explanation</u></em>
The given proportions are.....
and 
From the second proportion, we will get....

Now, we will plug this
into the first proportion. So we will get....

So, the values of x and y are 0.2 and 0.4 respectively.