Question

determine o valor de x e y x+y=13 x-y=1

Answer 1

Resposta:

2x + y = 13

x - y = -1

x = -1 + y

2x + y = 13

2(-1 + y) + y = 13

-2 + 2y + y = 13

-2 + 3y = 13

3y = 15

y = 5

x = -1 + y

x = -1 + 5  

x = 4