Please help me evaulate the seires?

enter image source here

1 Answer
May 2, 2018

enter image source here

(3(2)-2) + (3(3)-2) + (3(4)-2) + (3(5)-2) + (3(6)-2)(3(2)2)+(3(3)2)+(3(4)2)+(3(5)2)+(3(6)2)

4 + 7 + 10 + 13 + 16 = 504+7+10+13+16=50