Question

Use sigma notation to represent the sum of the first seven terms of the following sequence: 4, 10, 16, …

Answer 1

154 I think

Explanation:

Answer 2

Answer: 154

Explanation:

`a_1=4,\ d=6\quad \rightarrow \quad a_n=4+6(n-1)\quad \rightarrow \quad a_n=6n-2\\\\\\\sum^7_(n=1)6n-2\\\\\\a_1=4\\a_7=40\\\\\\S_n=(a_1+a_7)/(2)\cdot n\qquad =(4+40)/(2)\cdot 7\qquad =22\cdot 7\qquad =\large\boxed{154}`