Question

I don’t know how to do this page and it seems simple I just cant remember how to do it

Answer 1

So, we have the expressions:

$f(1)=2\text{ and }f(n)=f(n-1)+7$

Lets try to find the firsts numbers of this sequence:

$f(1)=2$$f(2)=f(1)+7\rightarrow f(2)=2+7\rightarrow f(2)=9$$f(3)=f(2)+7\rightarrow f(3)=(2+7)+7\rightarrow f(3)=2+2\times7\rightarrow f(3)=16$$f(4)=f(3)+7\rightarrow f(4)=(2+2\times7)+7\rightarrow f(4)=2+3\times7=23$

If we continue the sequence, we can see the we can use the followed formula:

$f(n)=2+(n-1)\times7$

To find the 30th number of the sequence, we just need to put 30 in the local of n:

$f(30)=2+(30-1)\times7\rightarrow f(30)=2+29\times7=205$

So, our 30th number of the sequence is 205.