Answer:
20 and 25.
Step-by-step explanation:
Given:
They both teach total 45 yoga classes each week.
Erica teaches 15 fewer than twice as many as Bo.
To find:
How many classes does each instructor teach per week = ?
Solution:
Let number of classes are taken by Bo = 
Then number of classes are taken by Erica =
(given)
Total number of classes are taken by both = 45 (given)
According to the question.
+
= 45

By adding both side by 15

By dividing both side by 3

number of classes are taken by Bo =
= 20
number of classes are taken by Erica = 
= 
Therefore, number of classes are taken by Bo and Erica is 20 and 25.
P=2L+2W
P-2W=2L
P/2-W=L
L=P/2-W
The unit rate is another way of saying speed, so we divide the distance over the time. We can pick on any row
If we pick row 1, then, speed = distance/time = 90/2 = 45
Row 2 says the same thing: 135/3 = 45
So does row 3: 225/5 = 45
and so on
Because the speed is 45 mph, the unit rate is 45 miles in one hour. The term "unit" implies how much distance can be covered in one unit of time, in this case 1 hour.
You have the correct answer. Nice work.