PLEASE HELP WILL GIVE MEDAL AND FAN !!!!!!!

What is the 43rd term of an arithmetic sequence with a rate of increase of -6 and a11 = 12?

Question

PLEASE HELP WILL GIVE MEDAL AND FAN !!!!!!!

What is the 43rd term of an arithmetic sequence with a rate of increase of -6 and a11 = 12?

anonymous · Answer

what do you mean by all?

anonymous · Answer

Its a 11 (the letter a and the number eleven) @cindyxluu

anonymous · Answer

i can help you with this since I have already learned about arithmetic sequence and geometric sequences but I still don't understand what you mean by a 11 = 12

if you can clarify that would be awesome

anonymous · Answer

ill draw it out @cindyxluu

anonymous · Answer

|dw:1426719376753:dw|

anonymous · Answer

oh ok that helps. let's get right to it then

anonymous · Answer

ok @cindyxluu

thesmartone · Answer

Arithmetic series
$\Large\sf a_n= a_1 +(n-1)d$

thesmartone · Answer

They have told you that the rate of increase is -6. So $\sf d=-6$

thesmartone · Answer

Also they have told you that $\sf a_{11}=12$

thesmartone · Answer

Plug that all in to your formula, I gave you above, you get:

$\sf\Large a_{11}=a_1+(11-1)\times(-6)$

Solve for $\sf a_1$. Once you get the value, plug it into the orignal formula I gave you, and plug in $\sf d=-6$ and plug in $\sf n=43$ And whatever you get as the answer then is your answer :)