Сложить дроби

a) 5/9 + 2/3

б) 1/12+3/4

в) 1/2 + 3/8

г) 17/1000+81/100

Вычесть дроби

а) 11/16 - 3/8

б) 5/6 - 5/12

в) 4/7-8/21

г) 17/30 - 4/15

А) 11/9 б) 13/12 в) 7/8 г) 980/1000 А) 5/16 б) 5/12 в) 4/21 г) 9/30

1) (5/9) + (2/3) = (5/9) + (6/9) = 11/9 = 1 (2/9) ; 2) (1/12) + (3/4) = (1/12) + (9/12) = 10/12 = 5/6; 3) (1/2) + (3/8) = (4/8) + (3/8) = 7/8; 4) (17/1000) + (81/100) = (17/1000) + (810/1000) = 827/1000 = 0,827; 5) (11/16) - (3/8) = (11/16) - (6/16) = 5/16; 6) (5/6) - (5/12) = (10/12) - (5/12) = 5/12; 7) (4/7) - (8/21) = (12/21) - (8/21) = 4/21; 8) (17/30) - (4/15) = (17/30) - (8/30) = 9/30 = 3/10 = 0,3