# WRITE A RULE FOR THE nth TERM OF THE ARITHMETIC SEQUENCE THEN FIND a_25: {1.6,4,6.4,8.8,11.2,…} *

WRITE A RULE FOR THE nth TERM OF THE ARITHMETIC SEQUENCE THEN FIND ${a}_{25}$: {1.6,4,6.4,8.8,11.2,…} *

You can still ask an expert for help

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

tabuordg

Answer: ${a}_{n}=2.4n-0.8,{a}_{25}=59.2$
We know an arithmetic sequence has the same difference for every two consecutive terms. So, the difference is $4-1.6=2.4$.
Then, note that the nth term of an arithmetic sequence is the first term plus $\left(n-1\right)×$ the difference. Thus, ${a}_{n}=1.6+2.4×\left(n-1\right)=2.4n-0.8$.

Then, ${a}_{25}=2.4×25-0.8=60-0.8=59.2$.