Question

4 Use the sequence below to complete each task. -6, 1, 8, 15, ... a. Identify the common difference (a). b. Write an equation to represent the sequence. C. Find the 12th term (a) our Wilson (All Things Algebral. 2011 Enter your answer(s) here

Answer 1

we have

-6, 1, 8, 15, ...

so

a1=-6

a2=1

a3=8

a4=15

a2-a1=1-(-6)=7

a3-a2=8-1=7

a4-a3=15-8=7

so

the common difference is

d=7

Part 2

write an equation

we have that

The equation of a general aritmetic sequence is equal to

an=a1+(n-1)d

we have

d=7

a1=-6

substitute

an=-6+(n-1)7

an=-6+7n-7

an=7n-13

Part 3

Find 12th term

we have

n=12

a12=-7(12)-13

a12=71