Question

17th term of an arithmetic sequence is 23 and 23rd term is 17 find the first time and common differenc

Answer 1

Answer:

Step-by-step explanation:

first term=a

common difference=d

nth term=an

so a+16d=23 ⇒a=23-16d

    a+22d=17⇒a=17-22d

equating the two values of a⇒23-16d=17-22d⇒6d=-6⇒ d= -1

a=23-16d=23-(16 * -1)=23- -16=23+16=39

so a=39 AND d=-1

hope this helps you

thank you

    a+

Answer 2

Answer:

Step-by-step explanation:

THIS TYPE OF QUESTION THE COMMON DIFFERENCE ALWAYS BE '-1'

T₁₇ = A + 16D

23 = A + -16

⇒A=39