## vivianrush 2 years ago Algebra 2 help please

1. vivianrush

2. Grazes

$\sum_{k=1}^{18}7x-4$ 18 is the stopping point because it is the number of rows. You start from 1 row to 18 rows. When you start with k=1, you can substitute for x in 7x-4---> 7(1)-4=3 so that's right in the sequence 3+....

3. Grazes

Can you do b? Moreover, have you learned the formula for partial sums?