Posts by livvy
Total # Posts: 3
the 20th sum of an arithmetic progression is -7 and the sum of the first 20 terms is 620. find the 1st and 30th terms i am looking at using S20 = a(1-rn)/l-r = 620. but i am reallys tuck and think i am very wrong. please help.
When did australia become a nation?? please i really need it!! my assignment is due tomorrow!!!