(2/5)÷(х3/5-1/5)-1/5=1/20
(2/5)÷(х3/5-1/5)=1/4
(2/5)=1/4(х3/5-1/5)
х3/20-1/20=8/20
х3/20=9/20
х3=9
х=3
(2/3)÷(х5/6-1/6)+1/3=7/9
(2/3)÷(х5/6-1/6)=4/9
2/3=4/9(х5/6-1/6)
2/3=х10/27-2/27
х10/27=20/27
х10=20
х=2
(3/4)÷(х1/8-3/8)-1/2=5/14
(3/4)÷(х1/8-3/8)=6/7
3/4=6/7(х1/8-3/8)
3/4=х3/28-9/28
х3/28=3/4+9/28
х3/28=30/28
х3=30
х=10