Respuesta :

Answer:

1.43

Step-by-step explanation:

9kg cost= 12.87

1kg cost= 12.87/9 =1.43

9kg book cost=12.87

1kg book will cost

[tex]\\ \rm\longmapsto \dfrac{12.87}{9}[/tex]

[tex]\\ \rm\longmapsto 1.43[/tex]