First, the dot stands for the "product". You have to multiply.
5/8* 2/7
= [5/ (2*4)]* (2/7)
= 5/4* 1/7 (because 2 and 2 cancel out)
= (5*1)/ (4*7)
= 5/28
The final answer is 5/28~
The answer is : Sn = S(n-1) + n
I think u do the ones in the parenthesis first bc of PEMDAS since it's both negative it become positive and u can cross out both the 2's and that leaves u with 1/7 and then u just times 1/7 with 8 and then u get 8/7
hoped this helped! :)
