Resposta :
{x-y= -5 (5) {8x+5y=12 {5x - 5y = - 25
{8x +5y = 12
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
13x ////////= -13 ---> x = -1
x-y= - 5 ---> -1-y = -5 ---> y = 4
x³ + y³ = (-1)³ + 4³ = -1 + 64 = 63
{8x +5y = 12
¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨¨
13x ////////= -13 ---> x = -1
x-y= - 5 ---> -1-y = -5 ---> y = 4
x³ + y³ = (-1)³ + 4³ = -1 + 64 = 63