Answer:
The first one
Step-by-step explanation:
On a graph, if the line starts at the origin, where the 0 is, which is the center in this case, it is proportional
On a table, if the numbers all the have the same rate of change, which is y/x, then it is proportional
Answer: 
Step-by-step explanation:
Given
Population of dust particle doubles every 30 minutes
If the initial sample is 21 grams
The model to predict the population will be

Where t=time in hours
A day has 24 hours . So, for 2 days time is 48 hours
Population is given by
Answer:
the probability of drawing a red would be 12/60, or 1/5, which is 0.2 or 20%
Answer:
= 21i
Step-by-step explanation:
√-9 = 3i
= 7 . 3i
Multiply the numbers: 7 . 3 = 21
= 21i
Hope this helps!
Answer:
155
Step-by-step explanation:
because he's skipping