1A) When f(n) = 12, what is the value of n?

Can't answer this

Step-by-step explanation:

For this question, I think you need to read more informations, find out the function

After you find out the function,

Replace f(x) as 12 and replace x with n

After that, try to solve it.

Good luck.

a28=58

step-by-step explanation:

a1=a1+(n-1)d

a28= 4+ (28-1)2

a28=4+(27)(2)

a28=4+54

a28=58