c.
The number of students is represented with S, to show 2 times that number it is shown as 2S, a less than is word problem jargon for minus. So it is 2S-21.
Answer:
A
Step-by-step explanation:
The first answer is correct because we have a decay factor.
The sample is losing mass, so the number that is being multiplied by a power of x must be less than 1.
If the second answer were used, then the sample would be gaining mass.
The volume is 214*8*2012
=3,444,544
The slope is already given in the question so we can find the y-intercept.
Slope-intercept form: y = mx + b
3 = 4(-2) + b
3 = -8 + b
3 + 8 = -8 + b + 8
11 = b
Now, we can write the equation.
y = 4x + 11
Best of Luck!