My little sister, savannah has a piggy bank, she wants to fill it. She started with 5pennies. Everyday when I come home

Question

Needs to be in a arithmetic or goemetric sequences

Answer 1

General formula says a_n = a₁ + (n-1)d

In plain English, that says that the number of items (pennies) on any (a_n) day is equal to the number that she started with (a_{1) plus the common difference (the number of pennies added each day) times (n-1)}

Let's plug in what we know: 

 

a₁ = 5

d = 3

 

an = 5 + (n-1)3

 

let's distribute: 5 + 3n -3

Combine like terms: 3n +2

 

So, on day 4, she'll have 3(4) +2 = 14

on day 5, she'll have 3(5) + 2 = 17

 

etc...