Question

Write in summation notation 13. 20 + 22 + 24 + ... + 36

Answer 1

Given the expression:

20 + 22 + 24 + ..... + 36

Let's write in summation notation.

Summation notation can be said to be the addition of a sequance of numbers.

From the sequence, we have:

Common difference = 22 - 20 = 2

Number of terms = 9

Apply the formula:

`\sum ^n_(i\mathop=1)a+d(i-1)`

Where:

n = upper limit (number of terms)

i = 1 ==> lower limit

Initial value, a = 20

d = common difference = 2

To write in summation notation, we have:

`\sum ^9_(i\mathop=1)20+2(i-1)`

ANSWER:

`\sum ^9_{i\mathop{=}1}20+2(i-1)`