that thang be arithmatik sequens . . . step 1...chaenj all terms tu POSITIV...kan put "-" bak on at the end . . . start=5, step size=2, last=17 . . . it hav 7 terms, averaej=(start+last)/2=(5+17)/2=11 . . . sum=(num terms)*averaej=7*11=77 . . . not chaenj sum tu -77