Answer:
a. the number of people at Friday's, Saturday's, and Sunday's performances combined.
Step-by-step explanation:
The reason this information is needed to solve this problem is because we are looking to find the number of people who attended Saturday's performance. Without any information on Saturday's performance, there is no way to solve the problem. We are given the number of people on Friday and Sunday's performance, but are not given a total amount of people on all performances.
Let the two numbers be x and y where x is greater than y.
So;
x + y = 3.1 ... (i)
2x - 3y = 7 ... (ii)
This forms a set of simultaneous equations (i) and (ii)
Solving the simultaneous equations by elimination;
We multiply (i) by 2 and (ii) by 1 to get:
2x + 2y = 6.2 ... (i)
2x - 3y = 7 ... (ii)
Subtracting (i) - (ii) we get;
5y = -0.8
y = -0.8/5 = -0.16
x = 3.1 - -0.16 = 3.26
The numbers are 3.26 and -0.16.