{x + y = -5 {x - 2y= 5 tentukan nilai x dan y

x + y = -5
x = -5 - y ... (1)

x - 2y = 5 ... (2)

»Substitusi (1) ke (2)
-5 - y - 2y = 5
-3y = 10
y = -10/3

»Substitusi y = -10/3 ke (1)
x = -5 - (-10/3)
x = -5/3