Question

X+y=10
X+3y=14
Qual o valor que essa aqui dar ?

Answer 1

x+y=10 => x=10-y
x+3y=14
substituindo...
10-y+3y=14
10+2y=14
2y=14-10
2y=4
y=4/2
y=2

x=10-y
x=10-2
x=8

S={8;2}