Find the value of a4 for this geometric series (i’ll add you on discord if you solve my guy and guyetts)

The value of a4 is 6

Step-by-step explanation:

* Lets revise the rule of the geometric series

- There is a constant ratio between each two consecutive numbers

- Ex:

# 5  ,  10  ,  20  ,  40  ,  80  ,  ………………………. (×2)

# 5000  ,  1000  ,  200  ,  40  ,  …………………………(÷5)  

* General term (nth term) of a Geometric series:

- a1 = a  ,  a2 = ar  ,  a3  = ar2  ,  a4 = ar3  ,  a5 = ar4

- an = ar^n-1, where a is the first term , r is the constant ratio

  between each two consecutive terms  and n is the position

  of the number in the series

* Now lets solve the problem

- The rule of the series is  2/9 (3)^n - 1

∴ a = 2/9 and r = 3

- To find a4 put n = 4

∴ a4 = 2/9 (3)^(4 - 1) = 2/9 (3)³ = 2/9 (27) = 6

∴ The series is 2/9 , 2/3 , 2 , 6 ,

* The value of a4 is 6

y < -3

step-by-step explanation:

-3y - 2 > 7

-3y -2 + 2 > 7+2

-3y > 9

-3y/-3 < 9/-3   (change the inequality sign when multiplying or dividing by a negative number)

y < -3

question: use the following table of a school bus during morning pickups to calculate its average speed between 2.8 km and 4.2 km

answer: 42 km/h

explanation: 1.4/0.033 42.42424 = 42 km/h

question answered by

(jacemorris04)