6m +m-35=21
7m-35=21
7m=21+35
7m=56
m=56÷7
m=8
17n+14n-145=134
31n-145=134
31n=134+145
n=279
n=279÷31
n=9
5n+9n+32=200
14n+32=200
14n=200-32
14n=168
n=168÷14
n=12
(x+57)÷7=12
x+57=12×7
x+57=84
x=84-57
x=27
(27+57)÷7=12
(161-y)÷16=9
161-y=9×16
161-y=144
y=161-144
y=17
(161-17)÷16=9
112÷(17+x)=4
17+x=112÷4
17+x=28
x=28-17
x=11
112÷(17+11)=4