Greetings :)
To find slope of two points we will need to use this equation: 
( 6 , -12 ) ( 15 , -3 )
Now let's replace the equation with the numbers. (it will be a fraction).
= 
The equation equals 9 over 9, which also equals 1.
The slope of the line is 1.
Answer:
4
Step-by-step explanation:
If ten people each get three slices, they will need 30 pieces.
10 x 3 = 30
Each pizza has 8 slices, so we divide 30 by 8 to get the number of pizzas needed.
30 / 8 = 3.75
You can't buy 3.75 pizzas, so you must get 4 to ensure everyone gets enough.
The answer is A. Hope this helps