9.3 project

 $a_{20\ }\ for\ a_{1\ }=\ 15,\ d\ =-8$  

• -135

• 137

• -137

• 136

 $12,\ 3,\ -6,\ ...$  

•  $a_{n\ }=\ -9n\ =\ 21$  

•  $a_n=9n\ +21$  

•  $a_{n\ }=-9-21$  

• N0 answer

Find the five arithmetic means between -18 and 36.

• 9,0,9,17,27

• -9,1,9,7,30

• -9,0,9,18,27

• 9,0,9,18,27

Find the sum of each arithmetic series.

2 + 4 + 6 + ... + 100

• 2551

• -2551

• 2552

• 2550

 $a_1=-24,\ a_{n\ }=\ 288,\ S_{n\ }=\ 5280$  

• -24, -16, -8

• 24, -16, -8

• -24, -16, 8

• 24, 16, 8

 $Find\ \sum_{m=9}^{21}\left(5m\ +6\right).$  

• F. 972

• G. 1053

• H. 1281

• J. 1701