обратите в десятичные дроби 9/20 7/40 11/400 21/168 35/280 47/376

9/20 = (9*5) / (50*5) = 45/100 = 0,45

7/40 = (7*25) / (40*25) = 45/100 = 0,175

11/400 = (11*25) / (400*25) = 275/10000 = 0,0275

21/168 = (21:21) / (168:21) = 1/8 = (1*125) / (8*125) = 0,125

35/280 = (35:35) / (280:35) = 1/8 = 0,125

47/376 = (47:47) / (376:47) = 1/8 = 0,125

9/20=0.45; 7/40=0,175; 11/400 = 0,0275; 21/168=0,125; 35/280=0,125; 47/376=0,125