Hey there :)
To find the slope with <em>two points</em> we will need to use the equation 

( 3 , -20 ) ( 5 , 8 )
Here is what the equation should look like when replaced with the numbers (<em>it will be a fraction</em>) :

We know that <em>two negatives</em> cancel out and make a positive, so the numerator would actually be 8 + 20.
Solve the fraction and we get 
28 <em>divided</em> by 2 is 14. The slope is 14.
Answer:
Step-by-step explanation:
Half life is the time taken by a radioactive substance to reduce of half of its original size
If the half life of radium is 1600, this means that the original radioactive substance N0 have reduced to N0/2 after 1600 years
if we are given N0 = 1000grams
The amount of the substance that will remain after 1600 years will be N0/2 i.e 1000/2 = 500g
<em>Hence 500 grams of radium will be left after 600years</em>
1-.63=.37. so $0.63+$0.37=$1.00
The best option seems to be
A) <span>
efficiency and practicality.</span>
The Ethical behavior is conducting ones self in a way that is common with a certain set of values whether personal or institutional.