1) у - 5/20 = 5/8 - 3/10y - 1/4 = 5/8 - 3/10y - 1/4 = 25/40 - 12/40y - 1/4 = 13/40y = 1/4 + 13/40y = 10/40 + 13/40y = 23/40
Ответ: у = 23/40
2) 2/3 - (7/9 - а) = 1/32/3 - 7/9 + а = 1/36/9 - 7/9 + а = 3/9-1/9 + а = 3/9а = 3/9 + 1/9а = 4/9
Ответ: а = 4/9
1) у - 5/20 = 5/8 - 3/10
y - 1/4 = 5/8 - 3/10
y - 1/4 = 25/40 - 12/40
y - 1/4 = 13/40
y = 1/4 + 13/40
y = 10/40 + 13/40
y = 23/40
Ответ: у = 23/40
2) 2/3 - (7/9 - а) = 1/3
2/3 - 7/9 + а = 1/3
6/9 - 7/9 + а = 3/9
-1/9 + а = 3/9
а = 3/9 + 1/9
а = 4/9
Ответ: а = 4/9