Respostas

2014-09-02T23:09:27-03:00
2014-09-02T23:21:54-03:00
A) {2x + 5y = 25
{ x - 5y = 5
3x = 30
x= 30/3 = 10 x - 5y = 5 y = 1





b) {2x + 3y = 19
{x - y = -3 .(3)
{2x + 3y = 19
{3x - 3y = -9
5x = 10
x = 10/5 = 2
2x + 3y =19
2.2 + 3y = 19
3y = 19 - 4
3y = 15
y = 15/3 = 5