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# Evaluate the summation of negative 2 n minus 3, from n equals 2 to 10.

**Solution:**

We have to find the summation of negative 2 n minus 3, from n equals 2 to 10.

We can write it as

-2n - 3 where n = 2 to 10.

Substituting the values

n = 2 = -7

n = 3 = -9

n = 4 = -11

n = 5 = -13

n = 6 = -15

n = 7 = -17

n = 8 = -19

n = 9 = -21

n = 10 = -23

Here the common difference between the terms is -2

And the sum of the AP having known the first and the last terms is given by n(a_{1}+a_{9})/2

9(a_{1}+a_{9})/2

9(-7-23)/2= 9(-30)/2

=9(-15)

Here the total is -135.

Therefore, the summation is -135.

## Evaluate the summation of negative 2 n minus 3, from n equals 2 to 10.

**Summary:**

The summation of negative 2 n minus 3, from n equals 2 to 10 is -135.

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