SUM cells with equal values in an adjacent column.

Use this in F2:

Formula:

=IF(COUNTIF(C$2:C2;C2)=1,SUMIF(C:C,C2,E:E),"")

And use this in G2:

Formula:

=IF(COUNTIFS(C$2:C2,C2,D$2:D2,D2)=1,SUMIFS(E:E,C:C,C2,D:D,D2),"")

And extend formula down