Find the sum of the first 16 terms of the series 14+11+8+5 + ... - 82

-136

Step-by-step explanation:

This series can be written as: (14 - 3*0) + (14 - 3*1) + ... + (14 - 3*n)

The sum of the first 16 terms is:

14*16 - 0 - 3 - 6 - 9 - ... = 224 - 360 = - 136

This underlined bit can be calculated in many ways, I personally used my calculator, but there are formulas to do so.