What is the answer for 82-(72+1)

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

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?

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.