123k views
4 votes
What value of m will m+9, 2m-1, and 2m+7 are the consecutive terms of an

arithmetic progression?

User Sbeam
by
8.1k points

1 Answer

1 vote

9514 1404 393

Answer:

m = 18

Explanation:

In an arithmetic progression, the middle term of three is half the sum of the terms on either side.

a1 +a3 = 2(a2)

(m +9) +(2m +7) = 2(2m -1)

3m +16 = 4m -2 . . . . . . collect terms

18 = m . . . . . . . . . . . . . . add 2-3m

User Boniestlawyer
by
7.4k points