Answer:

Step-by-step explanation:
The half life is the amount of time it takes a substance to decay to half of its original amount.
Since the radioactive substance has a half life of 1000 years, there will be half of it left after 1000 years.
So, the fraction that will be left after 1000 years is 
Answer:
y-6 = -7x + 21
Step-by-step explanation:
Find the slope
(-8 - 6)/(5-3)
-14/2 = -7
Now find the formula
y-6=-7(x - 3)
y-6 = -7x + 21
Another way to write it is
y= -7x + 27
Options 1 and 3 are the correct answers
Hello!
First of all, let's find the slope, which is the rise/run. We have the points (-4,-3) and (-2,0). To get the run there, we move to the left two units. We rise up three units as well. Therefore our slope is positive. We have rise/run, which is 3/2 as our slope.
Now, b is the y-intercept, or when our line intersects with the y-axis. We can see that it intersects at a y-value of 3.
We can write our equation below.
y=3/2x+3
I hope this helps!