91-9x4=x+4x7
91-36=x+28
55=x+28
x=55-28
x=27
x-4x8=85-9x4
x-32=85-36
x-32=49
x=49+32
x=81
4x8+x=9x9-27
32+x=81-27
32+x=54
x=54-32
x=22
x-9x3=6x7+21
x-27=42+21
x-27=63
x=63+27
x=90
x+7x8=94-6x3
x+56=94-18
x=76-56
x=20
6x9+x=6x4+8x8
54+x=24+64
54+x=88
x=88-54
x=34
x+6x8=9x9
x+48=81
x=81-48
x=33
6x8-x=82-7x9
48-x=82-63
x=48-19
x=29
