Answer:
Step-by-step explanation:

3.579 is greater.
It is relatively closer to 4 than the other number. 3 and 3 are equal, 5 and 5 are equal, but 7 is greater than 6. Hope this helps :)
3.99 + 0.75b = 12.24
0.75b = 12.24 - 3.99
0.75b = 8.25
b = 8.25 / 0.75
b = 11.....there were 11 bulbs
The equation would be 4n=8000
to solve, divide 8000/4=2000, she has collected 2,000 signatures so far