diketahui a=25 3 per 2 dan b=8 2 per 3 maka nilai a-30b adalah

25.3/2 - 30 x 8.2/3 = 75/2 - 160/3 = 225/6 - 320/6 = -95/6 = - 15.5/6

a = 25 3/2 = 53/2
b = 8 2/3 = 26/3
a - 30 b = 53/2 - 30(26/3)
              = 53/2 - 10.26
              = 53/2 - 260
              = 53/2 - 520/2
              = -467/2
              = - 233 1/2