Why is this a problem?Question 1:

Use the arithmetic sequence of numbers 2, 4, 6, 8, 10… to find the following:

What is d, the difference between any 2 terms?

the differences can be written:

(4-2)=2, (6-4)=2, (8-6)=2, (10-8)=2.

the first term is 2, the second term is 2+2=4, the third term is 2+2+2=6, the n-th term is 2+2+....+2 (with n terms) which is equal to 2n.Question 2:

Using the formula for thenth term of an arithmetic sequence, what is 101st term?

Therefore the 101-st tem is 1x101=202.

You need to know the formula for the sum of an arithmetic progression.Using the formula for the sum of an arithmetic sequence, what is the sum of the first 20 terms?

S(n)=(1/2)n(2a+(n-1)d)

here first term a=2, common difference d=2 and n=20, so:

S(20)=(1/2)x20x(4+19x2)=420

RonL