Question

Resolva gráficamente

X + Y = 5
X - Y = 1

Answer 1

{x + y = 5
{x - y = 1

x = 5 - y
5 - y - y = 1

-y - y = 1 - 5

-2y = -4 (-1)

y = 4 / 2

y = 2

para x:

x + y = 5
x + 2 = 5
x = 5 - 2
x = 3