If ∑an=S\sum a_n = S∑an=S and ∑bn=T\sum b_n = T∑bn=T, what is ∑(an+bn)\sum (a_n + b_n)∑(an+bn)?
S⋅TS \cdot TS⋅T
S+TS + TS+T
S−TS - TS−T
Cannot be determined