Решите уравнения а) у - 13/51 = - 9/34 б) 2/3 - z = 0,4 в) 4/7 + t = 0,7 12

У - 13/51 = - 9/34
у = - 9/34 + 13/51
у = - 27/102 + 26/102
y = - 1/102

2/3 - z = 0,4
2/3 - z = 4/10
2/3 - z = 2/5
z = 2/3 - 2/5
z = 10/15 - 6/15
z = 4/15

4/7 + t = 7/10
t = 7/10 - 4/7
t = 49/70 - 40/70
t = 9/70