Answer: D. 19 Bo; 25 Erica
Step-by-step explanation:
Let x represent the number of yoga classes that Bo teaches in a week.
Let y represent the number of yoga classes that Erica teaches in a week.
Between the two of them, they teach 44 yoga classes each week. This means that
x + y = 44 - - - - - - - - - - -1
If Erica teaches 13 fewer than twice as many as Bo, it means that
y = 2x - 13
Substituting y = 2x - 13 into equation 1, it becomes
x + 2x - 13 = 44
3x = 44 + 13 = 57
x = 57/3 = 19
y = 2x - 13 = 2 × 19 - 13
y = 25