just need to multiply and axpand ?

40+35 is the answer of the Ixl question
I think maybe 3) would make the most sense because she wants a random sample of students and the other options are specific on the type of students.
If 12 types only last 4 days, and the rest last an average of 6, then the average amount of days that ALL the flowers wilt would be 5. To find the average, you add 6 and 4 to get 10, and since there is only 2 number we added togehter to get 10, you would divide 10 by 2 to get 5!
Translation?
Let x be the number.
x+4-(-8)
Solve?
x+12