Пошаговое объяснение:
25/28- 2/21= 25(7*4) - 2/(7*3)= (25*3) /84 - (2*4)/84= 75/84-8/84=67/84
40/143 + 39/110= 40/(11*13) + 39/(11*10)= 400/1430 + 507/1430=907/1430
2) 41/54- 35/72= 41/(9*2*3) - 35/(9*2*4)= (41*4)/216 - (35*3)/216=
164/216 - 105/216= 59/216
5) 43/140 + 41/150= 43/(2*7*10)+41/ (3*5*10)= (43*15)/2100 + (41*14)/2100=645/2100+574/2100=1219/2100
3) 20/21 - 3/14 = 20/(3*7) - 3 /(2*7)= (20*2)/42 - (3*3)/42=
40/42- 9/42 = 31/42
6) 73/80 -37/100 = 73/(2*4*10) - 37/(2*5*10)= (73*5)/400 - (37*4)/400= 365/400 - 148/400=217/400
Пошаговое объяснение:
25/28- 2/21= 25(7*4) - 2/(7*3)= (25*3) /84 - (2*4)/84= 75/84-8/84=67/84
40/143 + 39/110= 40/(11*13) + 39/(11*10)= 400/1430 + 507/1430=907/1430
2) 41/54- 35/72= 41/(9*2*3) - 35/(9*2*4)= (41*4)/216 - (35*3)/216=
164/216 - 105/216= 59/216
5) 43/140 + 41/150= 43/(2*7*10)+41/ (3*5*10)= (43*15)/2100 + (41*14)/2100=645/2100+574/2100=1219/2100
3) 20/21 - 3/14 = 20/(3*7) - 3 /(2*7)= (20*2)/42 - (3*3)/42=
40/42- 9/42 = 31/42
6) 73/80 -37/100 = 73/(2*4*10) - 37/(2*5*10)= (73*5)/400 - (37*4)/400= 365/400 - 148/400=217/400