Answer:
Lavania observed 39 fruit flies after 6 days of observation
Step-by-step explanation:
Let x be the number of fruit flies on the first day of Lavania's study.
After 6 days she had nine more than five times as many fruit flies as when she began the study.
Five times as many fruit flies as when she began the study = 5x
Nine more than five times as many fruit flies as when she began the study=5x+9
The expression to find the population of fruit flies Lavania observed after 6 days is 5x+9
If she observes 20 fruit flies on the first day of the study, then x=6, then

Answer:
28
Step-by-step explanation:
Given that 12.5% of students own at least 1 pet, then the percentage of students who do not own a pet is
100% - 12.5% = 87.5%
Calculate 87.5% of 32, that is
× 32
= 0.875 × 32 = 28 ← number of students who do not own a pet
The Q30X program and the Intensity program are both effective because the average participant 1-mile run time was reduced for each program, but the Intensity program is the more effective program because it yielded a greater decrease in the average participant 1-mile run time.
The first thing we will do in this case is to define variables:
x = number of individual tickets.
y = number of tickets per couple.
We have then that the system of equations that represents the problem is:
10x + 15y = 590
x + 2y = 68
Solving the system we have:
x = 32
y = 18
Substituting we have:
10 (32) + 15 (18) = 590
320 + 270 = 590
590 = 590
Equality is met, therefore the $ 5 bill belongs to the box.
Answer:
the $ 5 bill belong inside the cash box