Determine the number of terms n in each arithmetic series.
12) a1 = 13, d = 3, Sn = 1225

The number of terms n in arithmetic series is n=25

Step-by-step explanation:

We are given:

a₁ = 13

d = 3

Sₙ = 1225

We need to find number of terms i.e n

The formula used will be:

Putting values and finding n

Now, solving using quadratic formula to find value of n:

Putting values: a=3, b=23 and c=-2450

So, we get:

Since number of terms can't be negative so, n= 25

So, the number of terms n in arithmetic series is n=25

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

a is the right answer