Answer:
1568 lessons
Step-by-step explanation:
We know that Crystal and Willow did the same number of Duolingo lessons every day. So, in constructing an expression to model the total number of lessons completed by both people, we can multiply everything by 2:
Next, we can determine that they both completed 30 lessons a day for 26 days, since every Wednesday they only did 1 lesson, and there are 4 Wednesdays (in 4 weeks) every month, which is about 30 days:
Finally, we can add the 4 days of only doing one lesson they did on the Wednesdays:
Simplifying the expression, we get:
[tex]2(780 + 4)[/tex]
[tex]=2(784)[/tex]
[tex]= 1568[/tex]
So, Crystal and Willow completed 1568 lessons in total.