[tex]a+b=2800 \\ \\ b= \frac{70a}{100} =\ \textgreater \ b= \frac{7a}{10} \\ \\ a+ \frac{7a}{10} =2800 .amplificam\\ \\ 10a+7a=28000=\ \textgreater \ a=28000:17=\ \textgreater \ a=1647,05 \\ \\ b= \frac{7}{10} 1647,05=\ \textgreater \ b=1647,05:10*7=\ \textgreater \ \\ \\ b=1152,95lei.al2lea.muncitor[/tex]