217x+99=25 217x=25-99 217x= -74 X=-74/217
check the picture below.
The 20th term is -106
15,9,3,-3,-9,-15,-21,-28,-35,-41,-46 (10) -6 x 10 = -60
-60 + -46
-106
You're just subtracting by 6.
Answer:
you need a picture of the prism
