Вычислите: 3/5 - 4/5; 2/7 - (-3/7);

-1/2-1/4; - 2/9 - (-1/3); - 4,8-5,9; 7-9,13

найдите значения вырожения:

(3,5-2,9) - (3,7-9,1)

(2/5-2/3) - (2/7-3/5)

3/5-4/5=-1/5;

2/7 - (-3/7) = 5/7;

1/2-1/4=1/4;

-2/9 - (-1/3) = - 1/9;

-4.8-5.9=-10.7;

7-9.13=-2.13

(3.5-2.9) - (3.7-9.1) = 0.6 - (-5.4) = 0.6+5.4=6

(2/5-2/3) - (2/7-3/5) = (6/15-10/15) - (10/35-21/35) =

=-4/15+11/35=15/525=1/35