Question

quanto da esse sistema?

{3x+2y=4
{5x+4y=7

Answer 1

{3x + 2y = 4 . (-2)
{5x + 4y = 7

{-6x - 4y = -8
{ 5x + 4y = 7
============
-x = -1 . (-1)
x = 1

5x + 4y = 7
5.1 + 4y = 7
5 + 4y = 7
4y = 7 - 5
4y = 2
y = 2/4
y = 1/2 ou 0,5


s={ 1, 1/2 }