Really hard to make it out, especially the upper limit of the sum, but I think it reads
(not sure what is, but that's not very important)
Expand the sum as
Then just plug in whatever happens to be.
the equation for this situation is y=122+45. to solve the equation you would add 45 and 122 to get a total of 167lbs. in conclusion, grace's weight eight weeks ago was 167lbs.
4x and 6y
im not sure though
determine whether the series is arithmetic or geometric, the find the indicated...