Respuesta :

Answer:

81.5, 9, 180

Step-by-step explanation:

28.

c=9

9x9=81

a=1/2

81+1/2=81.5

29.

9x1/2=4.5

4.5x2=9

30.

15x15=225

9x5=45

225-45=180

hope this helps!!!