Resposta:
a) 71/18
b) 55/18
c) 14/9
d) 63/8
Explicação passo-a-passo:
simplificando elas, X ficaria 7/2 e Y 4/9.
a) 7/2 + 4/9=
63/18 + 8/18= 71/18
b) 7/2 - 4/9=
63/18 - 8/18= 55/18
c) 7/2 . 4/9= 28/18
d) 7/2 : 9/4= 63/8
