Question

How do you evaluate `\sum_{j=1}^6 3(2)^j`?

Answer 1

`sum_(j=1)^6 3(2)^j=378`

Explanation:

`sum_(j=1)^6 3(2)^j=3(2^1+2^2+2^3+2^4+2^5+2^6)`

`sum_(j=1)^6 3(2)^j=3(2+4+8+16+32+64)`

`sum_(j=1)^6 3(2)^j=3(126)`

`sum_(j=1)^6 3(2)^j=378`