How are these shapes similar and different

Add the two expressions 3.8b - 7 and 2.9b + 9 enter your answer in simplified form

In the diagram, be and ad pass throughthe center of circle o, and the area ofsector aoc is 47.45 square units. what isthe area of sector boc? use the value =3.14, and round your answer to two decimalplaces.22.33 square units25.12 square units

Idon't get undoing if its pass adding and subtracting so can someone ? x-2 over 5 = 18