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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(a1+a9)/2
9(a1+a9)/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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