You did give the correct answer .
Answer:
4 students
Step-by-step explanation:
The total number of students is given by:

Where N is the total number of students, A is the number of students that have taken Math 2A, B is the number of students that have taken Math 2B, and C is the number of students that have taken Math 2C:

4 students in Group A have taken all three classes.
*The number of students that have taken two classes has be subtracted so those students do not get counted twice
Step-by-step explanation:
(2c+c) + 12 =78
3c + 12 = 78
78 - 12 = 66
66 ÷ 3 = 22
22 + 22 + 22 + 12 = 78
{ C = 22 }
Answer:
Consistent and Independent System
Step-by-step explanation:
A system with at least one solution is a consistent system. A consistent system is said to be independent if it has <u>exactly one solution</u> (often referred to as the <em>unique</em> solution). The graphs intersect at exactly one point, which gives an ordered-pair (x, y) as the solution of the system.