a) 1/25-1/100x=0

б) 1/75+1/25x=0

в) 1/8-1/64x=0

г) 1/30+1/90x=0

1/25=1/100х  х=100/25  х=4
1/75=-1/25х  х=-25/75    х=-1/3
1/8=1/64х  х=64/8    х=8
1/30=-1/90х  х=-90/30    х=-3

1/25-1/100х=0
-100х=-25
х=-25:-100
х=0.25

1/75+1/25х=0
25х=-75
х=-75:25
х=-1/3

1/8-1/64х=0
-64х=-8
х=-8:-64
х=0.125

1/30+1/90х=0
90х=-30
х=-30:90
х=-0.333