1/2-1/4+2/5 = 10/20-5/20+8/20 = 13/20
2) 3/4-1/2+7/8 = 6/8-4/8+7/8 = 9/8=1 1/8
3) 1/3-1/9+1/6 = 6/18-2/18+3/18 = 7/18
4)5/6-2/3+1/4 = 10/12-8/12+3/12= 5/12
1/2+x=5/6
x=5/6-1/2
x=5/6-3/6
x=2/6
x=1/3
ответ: 1/3
a+1/4=3/4
a=3/4-1/4
a=2/4
a=1/2
ответ: 1/2
y-1/5=3/10
y=3/10+1/5
y=3/10+2/10
y=5/10
y=1/2
5/6-с=1/3
с=5/6-1/3
с=5/6-2/6
с=3/6
с=1/2
ответ:1/2
1/2-1/4+2/5 = 10/20-5/20+8/20 = 13/20
2) 3/4-1/2+7/8 = 6/8-4/8+7/8 = 9/8=1 1/8
3) 1/3-1/9+1/6 = 6/18-2/18+3/18 = 7/18
4)5/6-2/3+1/4 = 10/12-8/12+3/12= 5/12
1/2+x=5/6
x=5/6-1/2
x=5/6-3/6
x=2/6
x=1/3
ответ: 1/3
a+1/4=3/4
a=3/4-1/4
a=2/4
a=1/2
ответ: 1/2
y-1/5=3/10
y=3/10+1/5
y=3/10+2/10
y=5/10
y=1/2
ответ: 1/2
5/6-с=1/3
с=5/6-1/3
с=5/6-2/6
с=3/6
с=1/2
ответ:1/2