ЗАДАНИЕ 2 a) 1/8 - 1/10 + 1/4; б) 3/20 + 1/5 - 1/6; в) 3/4 - 4/25 - 7/20; г) 3/7 - 1/6 + 5/14.

a) 1/8 - 1/10 + 1/4 = (1*5)/(8*5) - (1*4)/(10*4) + (1*10)/(4*10) = 5/40 - 4/40 + 10/40 = (5 - 4 + 10)/40 = 11/40

Ответ: 11/40

б) 3/20 + 1/5 - 1/6 = (3*3)/(20*3) + (1*12)/(5*12) - (1*10)/(6*10) = 9/60 + 12/60 - 10/60 = (9 + 12 - 10)/60 = 11/60

Ответ: 11/60

в) 3/4 - 4/25 - 7/20 = (3*25)/(4*25) - (4*4)/(25*4) - (7*5)/(20*5) = 75/100 - 16/100 - 35/100 = (75 - 16 - 35)/100 = 24/100 = 6/25

Ответ: 6/25

г) 3/7 - 1/6 + 5/14 = (3*6)/(7*6) - (1*7)/(6*7) + (5*3)/(14*3) = 18/42 - 7/42 + 15/42 = (18 - 7 + 15)/42 = 26/42 = 13/21

Ответ: 13/21