Please help this is worth a lot of my grade:( Determine the 15th term of the sequence??

an = -3n+50

Nnnnneeedd 1.find the residual if you know the actual number is 5.2 and the predicted value is 4.8

5/6+7/8what is the answer sealsdbdbshd

Miranda is braiding her hair.then she will attach beads to the braid.she wants 1_3 of the beads to be red.if the greatest number of beads that will fit on the braid is 12,what other fractions could represent the part of the beads that are red?