Ngracem802 Ngracem802
  • 25-04-2018
  • Mathematics
contestada

If 2k, 5k-1 and 6k+2 are the first 3 terms of an arithmetic sequence, find k and the 8th term.

Respuesta :

LammettHash
LammettHash LammettHash
  • 25-04-2018
Consecutive terms in an arithmetic sequence differ by a constant [tex]d[/tex]. So

[tex]5k-1=2k+d[/tex]
[tex]6k+2=5k-1+d[/tex]
[tex]\implies\begin{cases}3k-d=1\\k-d=-3\end{cases}\implies k=2,d=5[/tex]

Denote the [tex]n[/tex]-th term in the sequence by [tex]a_n[/tex]. Now that [tex]a_1=2[/tex], we have

[tex]a_n=a_{n-1}+5=a_{n-2}+2\cdot5=\cdots=a_1+(n-1)\cdot5[/tex]

which means

[tex]a_8=2+(8-1)\cdot5=37[/tex]
Answer Link

Otras preguntas

How to go to go math books?
nesecito un ejemplo de anti preposicion
The area of a square rug is 196 square feet. what is the side length, in feet, of the rug?
Which cell part is most similar to human excretory system?
the length of a leg of an isoceles triangleis twice the length of the base. what is the minimum length of the base if the perimeter is at least 20 cm?
HELP PLEASE Which artist used flat shapes, bright colors, and decorative patterns to create a jazz rhythm? A. Edward Hopper B. Stuart Davis
fin the product of -3+1i and its conjugate
Why did Zen Buddhism appeal to samurai more than Pure Land Buddhism? A. Bushido stated Zen Buddhism was stated as the superior religion. B. Zen Buddhism encou
14 is 20% of what number What percent of 48 is 30 Find 10% of 95 thanks
How do you calculate the fundamental frequency of a pipe?