Question

I need help show work

Answer 1

Explanation:

That symbol is sigma, which is the sum of that equation from k = 1 to n = 4

Equation is 2(3^n-1)

Since we're going 1 to 4, the sum would be as follows (replacing n with 1, 2, 3, and 4

`2( {3}^(1 - 1)) + 2( {3}^(2 - 1)) + 2( {3}^(3 - 1)) + 2( {3}^(4 - 1)) = {?}`

`2(1) + 2(3) + 2(9) + 2(27) =`

`2 + 6 + 8 + 54 = 70`