1)4/15-(y+3/25)=1/25
y+3/25=4/15-1/25
y+3/25=17/75
y=17/75-3/25
y=8/75
Проверка:4/15-(8/75+3/25)=1/25
2)(8цел3/14-у)÷3/7=17
8цел3/14-у=17×3/7
8цел3/14-у=51/7
8цел3/14-у=7цел2/7
у=8цел3/14-7цел2/7
у=13/14
Проверка:(8ц3/14-13/14)÷3/7=17
3)3цел1/16÷(х-5/16)=7/8
х-5/16=3ц1/16÷7/8
х-5/16=7/2
х=7/2+5/16
х=61/16
х=3цел13/16
Проверка:3ц1/16÷(3ц13/16-5/16)=7/8