Question

Find the sum of a finite arithmetic sequence from n = 1 to n = 10, using the expression 3n − 8.

56

85

54

116

Answer 1

Hello,


`\sum_(i=1)^(10)\ (3*i-8)\\ =3*(\sum_(i=1)^(10)\ i )-8*10\\ =3*(1+10)*10/2 -80\\ =165-80=85`

Answer B

Answer 2

we are given the function 3n - 8 and is asked in the problem to determine the sum of the terms in which n is from 1 to n is equal to 10. In this case, we substitute each number to the function and add their values. The answer to this problem therefore is 85.