In an arithmetic sequence, the 23rd term is $\frac{1}{4},$ and the $33$rd term is $-\frac{1}{5}$. What is the $43$rd term?
First, we must figure out what the common difference in the arithmetric sequence is. Let's let that be d.
From the problem, we have the equation
1/4+10d=−1/510d=−1/5−1/4=−9/20d=−9/200
Now, we can use all the information we have to find the 43rd term. We have
−1/5+10d=−1/5+10(−9/200)=−1/5−9/20=−65/100=−13/20
So our answer is -13/20.
Thanks! :)