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# Can you find the sum of the summation of 3 i minus 15, from i equals 2 to 7?

The summation is the sum of consecutive terms of a sequence. The summation brings consecutive terms together to make a new total.

## Answer: -9 is the sum of the summation of 3 i minus 15, from i equals 2 to 7.

Let's explore the summation formulas.

**Explanation: **

To find: The summation of 3 i minus 15, from i equals 2 to 7.

First we have to write 3 i minus 15, from i equals 2 to 7 in mathematical form, it can be writtenn as,

\(\sum_{2}^{7}(3i-15)\)

Now, putting the value of i from 2 to 7:

\(\sum_{2}^{7}(3i-15)\) = ((3 × 2) - 15) + ((3 × 3) - 15) + ((3 × 4) - 15) + ((3 × 5) - 15) + ((3 × 6) - 15) + ((3 × 7) - 15)

\(\sum_{2}^{7}(3i-15)\) = (6 - 15) + (9 - 15) + (12 - 15) + (15 - 15) + (18 - 15) + (21 - 15)

\(\sum_{2}^{7}(3i-15)\) = - 9 - 6 - 3 + 0 + 3 + 6

\(\sum_{2}^{7}(3i-15)\) = - 9

### Thus, -9 is coming as the summation of 3 i minus 15, from i equals 2 to 7.

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