The sums of n terms of two arithmetic progressions are in the ratio 5n+4: 9n+6. Find the ratio of their 18th terms.

179:321

Step-by-step explanation:

If Sn is the sum of the first n term of a sequence, the ratio will be expressed as:

Sn/S'n = 5n+4/9n+6

The sum of nth term of a sequence is expressed as

Sn = n/2[2a+(n-1)d]

The expression becomes

{n/2[2a+(n-1)d]}/{n/2[2a+(n-1)d']} = 5n+4/9n+4

Open the bracket

a+(n-1/2)d/a+(n-1/2)d' = 5n+4/9n+4

Since the 18th tern is expressed as

T18 = a+(18-1)d

T18 = a+17d

The expression becomes

T18/T'18 = a+(n-1/2)d/a+(n-1/2)d'

a+17d/a'+17d' = a+(n-1/2)d/a+(n-1/2)d'

Compare and contrast to get n

On comparing both sides of the equation

17 = n-1/2

n-1 = 17×2

n-1 = 34

n = 34+1

n = 35

If the nth term is 5n+4

18th term will be 5(35)+4 = 179

If the nth term is 9n+6

18th term will be 9(35)+6= 321

Hence the ratio of their 18th term will be 179:321

connie < felicia < stew

step-by-step explanation:

stew:

we need to find the slope

m = (y2-y1)/ (x2-x1)

    = (2650-795)/(10-3)

    = 1855/7

265 words per minute

connie:

we need to find the slope

m = (y2-y1)/ (x2-x1)

we have two points (0,0) and (4,800)

m = (800-0)/(4-0)

  m = 800/4

    200 words per minute

felicia:

260 words per minute

200< 260 < 265

connie < felicia < stew

none cuz there are no "following statements" regarding the question

step-by-step explanation: