Question

Okay so im taking this online math class and i dont know how to do these so can someone help me please.......

Answer 1

1)
A sequence is arithmetic if the difference between consecutive terms is constant.

$1,2,3,4,... \\ 2-1=3-2=4-3=1 \\ \hbox{arithmetic} \\ \\ 2,4,6,8,... \\ 4-2=6-4=8-6=2 \\ \hbox{arithmetic} \\ \\ 0,-2,-4,-6,... \\ -2-0=-4-(-2)=-6-(-4)=-2 \\ \hbox{arithmetic} \\ \\ 1,4,9,16,... \\ 4-1=3 \not= 9-4=5 \not= 16-9=7 \\ \hbox{not arithmetic}$

1, 4, 9, 16, ... is not an arithmetic sequence.

2)
$a_2=1 \\ d=-3 \\ \\ a_5=a_2+3d \\ a_5=1+3 \times (-3) \\ a_5=1-9 \\ a_5=-8$

The fifth term is -8.

Answer 2

Answer:

the answer for 1: is D:1,4,9,16

the answer for 2: is B:-8