Question

Can someone help me with this question? The topic is Systems of Equations. It says:

Bo and Erica are yoga instructors. Between the two of them, they teach 42 yoga classes each week. If Erica teaches 12 fewer than twice as many as Bo, how many classes does each instructor teach per week?
22 Bo; 20 Erica
20 Bo; 22 Erica
15 Bo; 27 Erica
18 Bo; 24 Erica

Answer 1

b = number of students Bo teaches.
e = number of student Erica teaches.

Between the two of them, they teach 42 yoga classes each week.
b + e = 42

Erica teaches 12 fewer than twice as many as Bo
2b - 12 = e -> 2b - e = 12


You now have the following system to solve
b + e = 42
2b - e = 12

Answer 2

@Lyrae Thanks so much!

Answer 3

Yw :)

And a small correction:
b and e are the number of classes they teach, not the amount of students. My mind were somwhere else :P