Resposta :
a) m + n=1 (-1)
4m + n=3
-m -n= -1
4m + n = 3
3m= 2
m= 2/3
2/3 + n=1
2/3 + 3n =1
3n= 1-2
n= -1/3
resposta: 2/3 e -1/3
4m + n=3
-m -n= -1
4m + n = 3
3m= 2
m= 2/3
2/3 + n=1
2/3 + 3n =1
3n= 1-2
n= -1/3
resposta: 2/3 e -1/3
a){m+n=1 (-1)
{4m+n=3(1)
-m - n = - 1
4m + n = 3
3m = 2
m = 2
3
m + n = 1==> n = 1 - m==>n = 1 - 2 ==> n = 3 - 2 ==> n = 1
3 3 3
b){2x+5y=6 (-2)
{3x+2y=-2 (5)
- 4x - 10y = - 12
15x + 10y = - 10
11x = - 22
x = - 2
2x+5y=6 ==> 5y = 6 -2x ==> 5y= 6-2.(-2)==> 5y= 6+4==>5y=10 ==> y= 2