[tex]a+b=5\ \textless \ =\ \textgreater \ a=5-b=\ \textgreater \ (5-b)+b=5=\ \textgreater \ 2b=10=\ \textgreater \ \\
b=5=\ \textgreater \ a+5=5=\ \textgreater \ a=5-5=\ \textgreater \ a=0\\
b+c=17\ \textless \ =\ \textgreater \ 5+c=17=\ \textgreater \ c=17-5=\ \textgreater \ c=12\\
5a+10b+5c\ \textless \ =\ \textgreater \ 5*0+10*5+5*12=\ \textgreater \ \\
0+50+60=\ \textgreater \ 0+110=110
[/tex]
