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
y = -
x + 
The equation of a line in slope-intercept form is
y = mx + c ( m is the slope and c the y-intercept )
rearrange 6x + 12y = 9 into this form
subtract 6x from both sides
12y = - 6x + 9 ( divide all terms by 12 )
y = -
x +
( which simplifies to )
y = -
x + 
The variable expression is x(shirt cost) + 8. The answer is x+8.
Answer:
A=60
Step-by-step explanation:
Add 28+20+12
A=60