Answer:
-1/3
Step-by-step explanation:
The common difference is how much it goes up by with each new number, so you can see that each time it goes down by 1/3. This means that the common difference is -1/3.
Answer:
f
Step-by-step explanation:
The variables would always be the letter
Ok well the only thing that makes since to me is that the triangle is a Equilateral Triangle, so all the sides are going to be the same. And if the perimeter is 24, then you divide that by 3, and you get 8. And if DEF is the midpoints of triangle ABC, then DEF is an upside down triangle in the triangle ABC. So all the sides of ABC are double whatever DEFs are. And DEFs were 8, so 8 times 2 is 16. And to get the perimeter you add that together 3 times and you get 48. So i'm not sure exactly how you would do this, but i'm pretty sure this is the way. If not i'm sorry i couldn't help. :(
Step-by-step explanation:

Answer:
180 - 84 = z
Step-by-step explanation:
all angles in a triangle should add up to 180. If both angles add up to 84 (42 + 42) all theres left to do is to substract 84 from 180 to find z :)