Question

PLEASE HELP ME GUYS!!! I need immediate help on the 2 above

Answer 1

The first answer is d and second answer is a

Explanation:

`\sum_(i=1)^(11){(3i^2-8)}`

`\sum_(i=1)^(11){(3i^2)}-\sum_(i=1)^(11)8`

`3\sum_(i=1)^(11){(i^2)}-\sum_(i=1)^(11)8`

3×n×(n+1)×(2n+1)/6 - 8×n

Putting n = 11

3×11×22×23/6 - 8×11

1430

The answer is 1430 option d

We have to find an expression for 10 terms of the series 3/4 + 9/8 +

3/2...................................................

`\sum_(i=1)^(10)(3n/8+3/8)`

Evaluating the the expansion we get the first option as answer by

substituting the values of i's

The answer is option a
`\sum_(i=1)^(10)(3n/8+3/8)`