What is the equation for an arithmetic sequence with a first term of 6 and a second term of 2?

an = 6 − 2(n − 1)
an = 6 + 2(n − 1)
an = 6 + 4(n − 1)
an = 6 − 4(n − 1)

Question

What is the equation for an arithmetic sequence with a first term of 6 and a second term of 2?

an = 6 − 2(n − 1)
 an = 6 + 2(n − 1)
 an = 6 + 4(n − 1)
 an = 6 − 4(n − 1)

byeeee · Answer

@dude

dude · Answer

Haven't done much arithmetic lately but do you have an idea on this?

byeeee · Answer

well i have the formula and i know the 1st term is 6 but i don't know about the second term

dude · Answer

So for 6 to go to 2, how much would you need to increase/decrease by?

byeeee · Answer

4

dude · Answer

|dw:1527719217611:dw|
This is the general equation

dude · Answer

In this case it is re-written as
$a_n=a_1+d(n-1)$
Which is the same thing, we know that $a_1=6$, so
$a_n=6+d(n-1)$
If you have to go down 4, then the rate is simply -4
$a_n=6-4(n-1)$

byeeee · Answer

ohhh

dude · Answer

If you want to check
$a_n=6-4(n-1)$

Substitute: (n=2 To find the second number) 
$a_2=6-4(2-1)$
$a_2=6-4(1)\
a_2=6-4\
a_2=2$

byeeee · Answer

so you have to actually put the -4 into the equation

dude · Answer

Yes

byeeee · Answer

thank you!