Решите уравнение. у+1/4=4/5-3/10; (4/5-х)+13/20=7/10; 2/3-(2/9+х)=1/3.

1) y + 1/4 = 4/5 - 3/10
    y + 0.25 = 0.8 - 0.3
    y + 0.25 = 0.5
    y = 0.25

2) (4/5 - x) + 13/20 = 7/10
     0.8 - x + 0.65 = 0.7
     0.8 - x = 0.05
     x = 0.75

3) 2/3 - (2/9 + x) = 1/3
    2/3 - 2/9 - x = 1/3
    6/9 - 2/9 - x = 3/9
    4/9 - x = 3/9
    x = 1/9