Evaluate the summation of negative 2 n minus 3, from n equals 2 to 10. - 270

-135

135

270

the summation of - 2n - 3, from n equals 2 to 10 is the sum of the first 10 term minus the first term.

Tn = - 2n - 3

T1 = - 2 (1) - 3 = - 2 - 3 = - 5

T10 = - 2 (10) - 3 = - 20 - 3 = - 23

Sn = n/2 (T1 + Tn)

S10 = 10/2 (-5 + (-23)) = 5 (-5 - 23) = 5 (-28) = - 140

Therefore, the summation of - 2n - 3, from n equals 2 to 10 = - 140 - (-5) = - 140 + 5 = - 135.