Respostas

2014-04-11T11:35:57-03:00
 \left \{ {{m+5n=5} \atop {4m+10n=16}} \right.

 \left \{ {{m+5n=5.(-1)} \atop {4m+10n=16:(2)}} \right.

 \left \{ {{-m-5n=-5} \atop {2m+5n=8}} \right.

Somam-se as equações: m=3

3+5n=55n=5-3=2n= \frac{2}{5}

m+n=3+ \frac{2}{5} = \frac{15+2}{5} = \frac{17}{5}