Resposta :
resolução!
X = cisnes
Y = girafas
x + y = 96 ________ x = 96 - y
2x + 4y = 242
2 ( 96 - y ) + 4y = 242
192 - 2y + 4y = 242
2y = 242 - 192
y = 50/2
y = 25
x = 96 - y
x = 96 - 25
x = 71
X = cisnes
Y = girafas
x + y = 96 ________ x = 96 - y
2x + 4y = 242
2 ( 96 - y ) + 4y = 242
192 - 2y + 4y = 242
2y = 242 - 192
y = 50/2
y = 25
x = 96 - y
x = 96 - 25
x = 71