Answer:
A total of 200 students were present at the basketball game
Step-by-step explanation:
Refer to the full question shown in the attached figure
Let
x be the total number of fourth graders
y represent the total attendees at the game
It is known that
The number of game attendees is four times the number of fourth graders
Thus
The linear expression is
-----> equation A
-----> equation B
Replace equation B into equation A and solve for y


Therefore
200 students were present at the basketball event
The water contains no larvae at temperatures of -10 degrees Celsius and 20 degrees Celsius.
Answer: observational study
Step-by-step explanation: