{[(7xa-5)+12}:4+5}x10-[(4+6)x5-42}=112
{[7xa-5)+12:4+5}x10-(10x5-42)=112
[(b-5)+3+5]x10-(50-42)=112
(c+3+5)x10-8=112
(d+5)x10-8=112
ex10-8=112
r-8=112
r=112+8
r=120
ex10=120
e=120:10
e=12
d+5=12
d=12-5
d=7
c+3=7
c=7-3
c=4
b-5=4
b=4+5
b=9
7xa=9
a=9:7
a=1rest2
