(b)The sum of n terms of a certain series is 3n² + 10n for all values Of n. Find the nth term and show that the series is an
arithmetical progression

Step-by-step explanation:

The nth term just mean how to work out the next number in he series. In this series of numbers, you have to square three n and add it onto 10 n to do this.

N is the term- the number it comes in the sequence.

Example:

2 3 4 5 6

2= the first terof the sequence

3= second term

4=3rd term

And so on

To work out what the next term is (6th term) you use this expression:

N+1

The first term is 2. As it is the first n=1. 1+1=2 so that works

The seco d term is 3. As it is the second term n=2. 2+1+3 so that works

And so on

This might help

But you have to do the rest

the answer is b. 60. each interior angle in 120, so the exterior angle must be 60 in order to add up to 180

step-by-step explanation:

stethere all not eveanp-by-step explanation: