Write the sum using summation notation, assuming the suggested pattern continues. - 10 - 2 + 6 + 14 + ... + 110

This is the sum of the arithmetic sequence:

10 - 2 + 6 + 14 + ... + 110

where: a 1 = - 10, d = 8

a n = 110

a n = a 1 + (n - 1) * d

110 = - 10 + (n - 1) * 8

110 = - 10 + 8 n - 8

110 + 10 + 8 = 8 n

128 = 8 n

n = 128 : 8

n = 16

∑ n = n/2 * (a 1 + a n)

∑ 16 = 16/2 * (-10 + 110) = 8 * 100 = 800

Answer:

The sum is 800.