Question

-4x+y=3
2x+3y=19
help me please

Answer 1

-4x +y = 3 (Multiplica por -3 pra anular y)
2x + 3y = 19

12x - 3y = -9
2x + 3y = 19
14x = 10
x = 10/14
x = 5/7

2.5/7 + 3y = 19
10/7 + 3y = 19
3y = 19 - 10/7
3y = 123/7
y = (123/7) / 3
y = 123 / (7.3)
y = 123 / 21
y = 41/7

Par ordenado x,y (5/7, 41/7)


Substituindo os valores de x e y nas equações:

2x + 3y = 19
2.5/7 + 3.41/7 = 19
10/7 + 123/7 = 19
133/7 = 19
19 = 19 

-4x +y = 3
-4.5/7 + 41/7 = 3
-20/7 + 41/7 = 3
21/7 = 3
3 = 3